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TUCoPS :: Unix :: General :: ciach066.txt

Vulnerability In Suidperl Sperl




__________________________________________________________

                       The U.S. Department of Energy
                    Computer Incident Advisory Capability
                           ___  __ __    _     ___
                          /       |     /_\   /
                          \___  __|__  /   \  \___
             __________________________________________________________

                             INFORMATION BULLETIN

                       Vulnerability in suidperl (sperl)

April 8, 1998 21:00 GMT                                          Number H-66a
______________________________________________________________________________
PROBLEM:       A problem has been identified in suidperl that allows a buffer
               overflow condition.
PLATFORM:      All Unix systems with Perl 4.x and Perl 5.x.
DAMAGE:        When calling this program with appropriately crafted
               parameters, unauthorized local users can execute arbitrary
               commands as root.
SOLUTION:      Apply the proper patch supply by vendor.
______________________________________________________________________________
VULNERABILITY  This vulnerability is being actively exploited.
ASSESSMENT:
______________________________________________________________________________

[ Appended on April 8, 1998 with additional vendor information ]

[ Start CERT Advisory ]

=============================================================================
CERT* Advisory CA-97.17
Original issue date: May 29, 1997
Last revised: --

Topic: Vulnerability in suidperl (sperl)
- ------------------------------------------------------------------------------

The CERT Coordination Center has received reports of a buffer overflow
condition in suidperl built from Perl 4.n and Perl 5.n distributions on UNIX
systems. By calling this program with appropriately crafted parameters,
unauthorized local users can execute arbitrary commands as root. This
vulnerability is being actively exploited.

The CERT/CC team recommends installing a vendor patch if one is available (see
Section III.B). Until you can do so, we recommend disabling suidperl (Section
III.A). Two other alternatives are to install suidperl or sperl from version
5.003 source code along with the patch provided in Appendix B of this
advisory (see also Section III.C), or upgrade to Perl version 5.004 (Section
III.D). Note that Perl4 is no longer supported.

We will update this advisory as we receive additional information.
Please check our advisory files regularly for updates that relate to your
site.

- ------------------------------------------------------------------------------

I.   Description

     On some systems, setuid and setgid scripts (scripts written in the C
     shell, Bourne shell, or Perl, for example, with the set user or group ID
     permissions enabled) are insecure due to a race condition in the
     kernel. For those systems, Perl versions 4 and 5 attempt to work around
     this vulnerability with a special program named suidperl, also known as
     sperl. This program attempts to emulate the set-user-ID and set-group-ID
     features of the kernel.

     There is a buffer overflow condition in suidperl built from Perl 4.n and
     Perl 5.n distributions earlier than version 5.004. If this program is
     called with appropriately crafted parameters, an attacker can execute
     arbitrary commands as root. This vulnerability is being actively
     exploited.

II.  Impact

     Users executing Perl scripts with the setuid bit set can execute
     arbitrary commands with the effective uid of the owner of the Perl
     script. Attackers can execute commands as root.


III. Solution

     Use the command in Section A to help you determine if your system is
     vulnerable and, if it is, to (optionally) disable the suidperl and sperl
     programs (see Section A). If you find that your system is vulnerable,
     replace the suidperl and sperl programs with new versions.

     Section B describes how to do that if your site uses versions of suidperl
     and sperl that are provided as part of a vendor-supplied distribution.
     Sites that installed suidperl and sperl programs themselves from the Perl
     source distribution should patch the distribution as described in Section
     C or upgrade to version 5.004 as described in Section D. Note that Perl4
     is no longer supported.

     A. Determine if your system is vulnerable and disable vulnerable programs

        To determine if a system is vulnerable to this problem and to disable
        the programs that are believed to be vulnerable, use the following
        find command or a variant. Consult your local system documentation to
        determine how to tailor the find program on your system.

        After you have run this command on all your systems, they will no
        longer be vulnerable. Note that after disabling the suidperl and sperl
        programs, they will no longer be able to emulate the set-user-ID and
        set-group-ID features of the kernel.

        You will need to run the find command on each system you maintain
        because the command examines files on the local disk only. Substitute
        the names of your local file systems for FILE_SYSTEM_NAMES in the
        example. Example local file system names are /, /usr, and /var.
        You must do this as root.

        Note that this is one long command, though we have separated
        it onto five lines using back-slashes.

             find FILE_SYSTEM_NAMES -xdev -type f -user root \
                    \( -name 'sperl4.[0-9][0-9][0-9]' \
                    -o -name 'sperl5.00[0-3]' \
                    -o -name 'suidperl' \) \
                    -perm -04000 -print -ok chmod ug-s '{}' \;

        This command will find all files on a system that are
            - only in the file system you name (FILE_SYSTEM_NAMES -xdev)
            - regular files (-type f)
            - owned by root (-user root)
            - named appropriately (-name 'sperl4.[0-9][0-9][0-9]'
                                    -o -name 'sperl5.00[0-3]'
                                    -o -name 'suidperl')
            - setuid root (-perm -04000)

        Once found, those files will
            - have their names printed (-print)
            - have their modes changed, but only if you type `y'
              in response to the prompt (-ok chown ug-s '{}' \;)


     B. Obtain and install the appropriate patch from your vendor

        If your vendor ships suidperl or sperl, you may be vulnerable and need
        a patch. Appendix A contains information provided by the following
        vendors. If your vendor is not on this list, please contact the vendor
        directly.

                Berkeley Software Design, Inc. (BSDI)
                Cray Research - A Silicon Graphics Company
                Data General Corporation
                Hewlett-Packard Company
                IBM Corporation
                Linux
                The Santa Cruz Operation, Inc. (SCO)
                Silicon Graphics, Inc. (SGI)

        Until you can install a patch, we recommend disabling suidperl.
        The find command above will help you do that. If you need
        suidperl or sperl, see the alternatives in Sections C and D below.


     C. Install suidperl or sperl from 5.003 source code and apply a patch.
        Follow the instructions below, which were provided by Chip Salzenberg.

        If you would like to keep using setuid Perl scripts, fix Perl
        yourself by following these steps:

        1. Go to your Perl 5.003 source directory, or else obtain a fresh
           Perl 5.003 distribution from

              http://www.perl.com/CPAN/src/5.0/perl5.003.tar.gz

           or another CPAN archive accessible to you.

           This file is approximately 1.5 megabytes in size.

        2. Using the "patch" program, apply the patch that is enclosed
           below in Appendix B.

        3. Build and install the patched Perl 5.003. (If you have never
           built Perl before, be sure to read the "INSTALL" file first.)

        Perl 5.003 binaries that have had this patch applied, and therefore
        are safe from all known attacks, can be identified by the
        output of the "perl -v" command: the "locally applied patches" list
        will include "SUIDBUF - Buffer overflow fixes for suidperl
        security".


     D. Install suidperl or sperl from 5.004 source code (no patch needed).

        If you would like to upgrade to Perl version 5.004, follow these
        steps:

        1. Obtain a fresh Perl 5.004 distribution from

              http://www.perl.com/CPAN/src/5.0/perl5.004.tar.gz

           or another CPAN archive accessible to you.

           This file is approximately 2.5 megabytes in size.

        2. Build and install Perl 5.004 according to the instructions
           given in the "INSTALL" file. Do NOT apply the patch.

           Perl 5.004 binaries, which are safe from all known attacks, can be
           identified by the output of the "perl -v" command: it should say
           "This is perl, version 5.004". (Unlike the 5.003 patch mentioned
           in Section C, the "locally applied patches" list will NOT include
           "SUIDBUF - Buffer overflow fixes for suidperl security". The fact
           that it is version 5.004 is sufficient in this case.)


==============================================================================

Appendix A - Vendor Information

Below is a list of the vendors who have provided information for this
advisory. We will update this appendix as we receive additional information.
If you do not see your vendor's name, the CERT/CC did not hear from that
vendor. Please contact the vendor directly.


Berkeley Software Design, Inc. (BSDI)
=====================================
  BSD/OS is vulnerable to the suidperl (sperl) buffer overflow problem. We
  will be releasing a patch for BSDI 3.0 and perl 5.003 and are currently
  working on patches for BSD/OS 3.0 and Perl 4.036. We will also be developing
  patches for the perl versions shipped with BSD/OS 2.1.


Cray Research - A Silicon Graphics Company
==========================================
  Cray Research does not ship perl as part of either Unicos or Unicos/mk.


Data General Corporation
========================
  The only perl executables that are shipped with DG/UX are:

  /bin/perl

  and

  /bin/perl5 /* in R420 */

  These are not set uid programs.

  Therefore,
  No versions of DG/UX are vulnerable to this problem.


Hewlett-Packard Company
=======================
  HP does not ship this product.


IBM Corporation
===============
  AIX versions do not have Perl as part of the standard product.
  However, the SP2's PSSP software does contain suidperl, but the
  program is not installed with the setuid bit set.

  IBM and AIX are registered trademarks of International Business Machines
  Corporation.


Linux
=====
  Red Hat 4.2 is not vulnerable
  Red Hat 4.1/4.0 you can get the upgraded RPM from ftp.redhat.com

  If you wish to check whether you have the fixed perl run perl -v and
  check for

        Locally applied patches:
          SUIDBUF - Buffer overflow fixes for suidperl security


The Santa Cruz Operation, Inc. (SCO)
====================================
  suidperl is not included in any SCO products.

  SCO CMW+ and SCO OpenServer do not have kernel support for setuid
  scripts, but you may have installed suidperl in order to emulate
  that functionality - in that case you should replace your version of
  perl with version 5.004, or patch your source code as noted in this
  advisory.

  SCO UnixWare does have safe kernel support for setuid scripts so
  that suidperl is not necessary.  If you have installed a version
  of perl that includes suidperl, you should remove suidperl and
  install a version of perl built so as not to require it.


Silicon Graphics, Inc. (SGI)
=============================
  At this time, Silicon Graphics does not have any public information for
  this suidperl/sperl issue.  Silicon Graphics has communicated with
  CERT and other external security parties and is actively investigating
  this issue.   When more Silicon Graphics information (including any
  possible patches) is available for release, that information will
  be released via the SGI security mailing list, wiretap.

  For subscribing to the wiretap mailing list and other SGI security
  related information, please refer to the Silicon Graphics Security
  Headquarters website located at:

        http://www.sgi.com/Support/Secur/security.html

============================================================================

Appendix B - Source Code Patch Information

The following patch information has been supplied by Chip Salzenberg. If you
built suidperl or sperl from 5.003 source code, we encouraged you to apply
this patch (see the explanation in Section III.C above).


Patch follows.

- ---------------------------------------------------------------------------

Index: patchlevel.h
***************
*** 41,42 ****
- - --- 41,43 ----
+       ,"SUIDBUF - Buffer overflow fixes for suidperl security"
        ,NULL
  };

Index: perl.c
*************** char *s;
*** 1212,1216 ****
  #  endif
  #endif
!       fputs("\n\t+ suidperl security patch", stdout);
        fputs("\n\nCopyright 1987-1996, Larry Wall\n",stdout);
  #ifdef MSDOS
- - --- 1212,1216 ----
  #  endif
  #endif
!       fputs("\n\t+ two suidperl security patches", stdout);
        fputs("\n\nCopyright 1987-1996, Larry Wall\n",stdout);
  #ifdef MSDOS

Index: gv.c
*************** gv_fetchfile(name)
*** 59,67 ****
  char *name;
  {
!     char tmpbuf[1200];
      GV *gv;

!     sprintf(tmpbuf,"::_<%s", name);
      gv = gv_fetchpv(tmpbuf, TRUE, SVt_PVGV);
      sv_setpv(GvSV(gv), name);
      if (*name == '/' && (instr(name,"/lib/") || instr(name,".pm")))
- - --- 59,80 ----
  char *name;
  {
!     char smallbuf[256];
!     char *tmpbuf;
!     STRLEN tmplen;
      GV *gv;

!     tmplen = strlen(name) + 4;
!     if (tmplen < sizeof smallbuf)
!       tmpbuf = smallbuf;
!     else
!       New(603, tmpbuf, tmplen + 1, char);
!     tmpbuf[0] = ':';
!     tmpbuf[1] = ':';
!     tmpbuf[2] = '_';
!     tmpbuf[3] = '<';
!     strcpy(tmpbuf + 4, name);
      gv = gv_fetchpv(tmpbuf, TRUE, SVt_PVGV);
+     if (tmpbuf != smallbuf)
+       Safefree(tmpbuf);
      sv_setpv(GvSV(gv), name);
      if (*name == '/' && (instr(name,"/lib/") || instr(name,".pm")))

Index: toke.c
*************** static char *scan_const _((char *start))
*** 22,26 ****
  static char *scan_formline _((char *s));
  static char *scan_heredoc _((char *s));
! static char *scan_ident _((char *s, char *send, char *dest, I32 ck_uni));
  static char *scan_inputsymbol _((char *start));
  static char *scan_pat _((char *start));
- - --- 22,27 ----
  static char *scan_formline _((char *s));
  static char *scan_heredoc _((char *s));
! static char *scan_ident _((char *s, char *send, char *dest, STRLEN destlen,
!                          I32 ck_uni));
  static char *scan_inputsymbol _((char *start));
  static char *scan_pat _((char *start));
*************** static char *scan_str _((char *start));
*** 28,32 ****
  static char *scan_subst _((char *start));
  static char *scan_trans _((char *start));
! static char *scan_word _((char *s, char *dest, int allow_package, STRLEN
*slp));
  static char *skipspace _((char *s));
  static void checkcomma _((char *s, char *name, char *what));
- - --- 29,34 ----
  static char *scan_subst _((char *start));
  static char *scan_trans _((char *start));
! static char *scan_word _((char *s, char *dest, STRLEN destlen,
!                         int allow_package, STRLEN *slp));
  static char *skipspace _((char *s));
  static void checkcomma _((char *s, char *name, char *what));
*************** static char * filter_gets _((SV *sv, FIL
*** 47,50 ****
- - --- 49,54 ----
  static void restore_rsfp _((void *f));

+ static char too_long[] = "Identifier too long";
+
  /* The following are arranged oddly so that the guard on the switch
statement
   * can get by with a single comparison (if the compiler is smart enough).
*************** int allow_tick;
*** 475,479 ****
        (allow_tick && *s == '\'') )
      {
!       s = scan_word(s, tokenbuf, allow_pack, &len);
        if (check_keyword && keyword(tokenbuf, len))
            return start;
- - --- 479,483 ----
        (allow_tick && *s == '\'') )
      {
!       s = scan_word(s, tokenbuf, sizeof tokenbuf, allow_pack, &len);
        if (check_keyword && keyword(tokenbuf, len))
            return start;
*************** register char *s;
*** 847,851 ****
        unsigned char un_char = 0, last_un_char;
        char *send = strchr(s,']');
!       char tmpbuf[512];

        if (!send)              /* has to be an expression */
- - --- 851,855 ----
        unsigned char un_char = 0, last_un_char;
        char *send = strchr(s,']');
!       char tmpbuf[sizeof tokenbuf * 4];

        if (!send)              /* has to be an expression */
*************** register char *s;
*** 872,876 ****
                weight -= seen[un_char] * 10;
                if (isALNUM(s[1])) {
!                   scan_ident(s,send,tmpbuf,FALSE);
                    if ((int)strlen(tmpbuf) > 1 && gv_fetchpv(tmpbuf,FALSE,
SVt_PV))
                        weight -= 100;
- - --- 876,880 ----
                weight -= seen[un_char] * 10;
                if (isALNUM(s[1])) {
!                   scan_ident(s, send, tmpbuf, sizeof tmpbuf, FALSE);
                    if ((int)strlen(tmpbuf) > 1 && gv_fetchpv(tmpbuf,FALSE,
SVt_PV))
                        weight -= 100;
*************** GV *gv;
*** 942,946 ****
  {
      char *s = start + (*start == '$');
!     char tmpbuf[1024];
      STRLEN len;
      GV* indirgv;
- - --- 946,950 ----
  {
      char *s = start + (*start == '$');
!     char tmpbuf[sizeof tokenbuf];
      STRLEN len;
      GV* indirgv;
*************** GV *gv;
*** 952,956 ****
            gv = 0;
      }
!     s = scan_word(s, tmpbuf, TRUE, &len);
      if (*start == '$') {
        if (gv || last_lop_op == OP_PRINT || isUPPER(*tokenbuf))
- - --- 956,960 ----
            gv = 0;
      }
!     s = scan_word(s, tmpbuf, sizeof tmpbuf, TRUE, &len);
      if (*start == '$') {
        if (gv || last_lop_op == OP_PRINT || isUPPER(*tokenbuf))
*************** yylex()
*** 1629,1633 ****
      case '*':
        if (expect != XOPERATOR) {
!           s = scan_ident(s, bufend, tokenbuf, TRUE);
            expect = XOPERATOR;
            force_ident(tokenbuf, '*');
- - --- 1633,1637 ----
      case '*':
        if (expect != XOPERATOR) {
!           s = scan_ident(s, bufend, tokenbuf, sizeof tokenbuf, TRUE);
            expect = XOPERATOR;
            force_ident(tokenbuf, '*');
*************** yylex()
*** 1645,1649 ****
      case '%':
        if (expect != XOPERATOR) {
!           s = scan_ident(s, bufend, tokenbuf + 1, TRUE);
            if (tokenbuf[1]) {
                expect = XOPERATOR;
- - --- 1649,1653 ----
      case '%':
        if (expect != XOPERATOR) {
!           s = scan_ident(s, bufend, tokenbuf + 1, sizeof tokenbuf - 1, TRUE);
            if (tokenbuf[1]) {
                expect = XOPERATOR;
*************** yylex()
*** 1748,1752 ****
                s++;
            if (s < bufend && isALPHA(*s)) {
!               d = scan_word(s, tokenbuf, FALSE, &len);
                while (d < bufend && (*d == ' ' || *d == '\t'))
                    d++;
- - --- 1752,1756 ----
                s++;
            if (s < bufend && isALPHA(*s)) {
!               d = scan_word(s, tokenbuf, sizeof tokenbuf, FALSE, &len);
                while (d < bufend && (*d == ' ' || *d == '\t'))
                    d++;
*************** yylex()
*** 1847,1851 ****
        }

!       s = scan_ident(s-1, bufend, tokenbuf, TRUE);
        if (*tokenbuf) {
            expect = XOPERATOR;
- - --- 1851,1855 ----
        }

!       s = scan_ident(s - 1, bufend, tokenbuf, sizeof tokenbuf, TRUE);
        if (*tokenbuf) {
            expect = XOPERATOR;
*************** yylex()
*** 1956,1960 ****
      case '$':
        if (s[1] == '#'  && (isALPHA(s[2]) || strchr("_{$:", s[2]))) {
!           s = scan_ident(s+1, bufend, tokenbuf+1, FALSE);
            if (expect == XOPERATOR) {
                if (lex_formbrack && lex_brackets == lex_formbrack) {
- - --- 1960,1965 ----
      case '$':
        if (s[1] == '#'  && (isALPHA(s[2]) || strchr("_{$:", s[2]))) {
!           s = scan_ident(s + 1, bufend, tokenbuf + 1, sizeof tokenbuf - 1,
!                          FALSE);
            if (expect == XOPERATOR) {
                if (lex_formbrack && lex_brackets == lex_formbrack) {
*************** yylex()
*** 1982,1986 ****
            TOKEN(DOLSHARP);
        }
!       s = scan_ident(s, bufend, tokenbuf+1, FALSE);
        if (expect == XOPERATOR) {
            if (lex_formbrack && lex_brackets == lex_formbrack) {
- - --- 1987,1991 ----
            TOKEN(DOLSHARP);
        }
!       s = scan_ident(s, bufend, tokenbuf + 1, sizeof tokenbuf - 1, FALSE);
        if (expect == XOPERATOR) {
            if (lex_formbrack && lex_brackets == lex_formbrack) {
*************** yylex()
*** 2016,2024 ****
                if (*s == '{' && strEQ(tokenbuf, "$SIG") &&
                  (t = strchr(s,'}')) && (t = strchr(t,'='))) {
!                   char tmpbuf[1024];
                    STRLEN len;
                    for (t++; isSPACE(*t); t++) ;
                    if (isIDFIRST(*t)) {
!                       t = scan_word(t, tmpbuf, TRUE, &len);
                        if (*t != '(' && perl_get_cv(tmpbuf, FALSE))
                            warn("You need to quote \"%s\"", tmpbuf);
- - --- 2021,2029 ----
                if (*s == '{' && strEQ(tokenbuf, "$SIG") &&
                  (t = strchr(s,'}')) && (t = strchr(t,'='))) {
!                   char tmpbuf[sizeof tokenbuf];
                    STRLEN len;
                    for (t++; isSPACE(*t); t++) ;
                    if (isIDFIRST(*t)) {
!                       t = scan_word(t, tmpbuf, sizeof tmpbuf, TRUE, &len);
                        if (*t != '(' && perl_get_cv(tmpbuf, FALSE))
                            warn("You need to quote \"%s\"", tmpbuf);
*************** yylex()
*** 2093,2097 ****

      case '@':
!       s = scan_ident(s, bufend, tokenbuf+1, FALSE);
        if (expect == XOPERATOR)
            no_op("Array",s);
- - --- 2098,2102 ----

      case '@':
!       s = scan_ident(s, bufend, tokenbuf + 1, sizeof tokenbuf - 1, FALSE);
        if (expect == XOPERATOR)
            no_op("Array",s);
*************** yylex()
*** 2129,2133 ****
                        : !GvHV(gv) )))
            {
!               char tmpbuf[1024];
                sprintf(tmpbuf, "Literal @%s now requires backslash",tokenbuf+1);
                yyerror(tmpbuf);
- - --- 2134,2138 ----
                        : !GvHV(gv) )))
            {
!               char tmpbuf[sizeof tokenbuf + 40];
                sprintf(tmpbuf, "Literal @%s now requires backslash",tokenbuf+1);
                yyerror(tmpbuf);
*************** yylex()
*** 2293,2297 ****
        keylookup:
        bufptr = s;
!       s = scan_word(s, tokenbuf, FALSE, &len);
       
        if (*s == ':' && s[1] == ':' && strNE(tokenbuf, "CORE"))
- - --- 2298,2302 ----
        keylookup:
        bufptr = s;
!       s = scan_word(s, tokenbuf, sizeof tokenbuf, FALSE, &len);
       
        if (*s == ':' && s[1] == ':' && strNE(tokenbuf, "CORE"))
*************** yylex()
*** 2338,2342 ****

                if (*s == '\'' || *s == ':' && s[1] == ':') {
!                   s = scan_word(s, tokenbuf + len, TRUE, &len);
                    if (!len)
                        croak("Bad name after %s::", tokenbuf);
- - --- 2343,2348 ----

                if (*s == '\'' || *s == ':' && s[1] == ':') {
!                   s = scan_word(s, tokenbuf + len, sizeof tokenbuf - len,
!                                 TRUE, &len);
                    if (!len)
                        croak("Bad name after %s::", tokenbuf);
*************** yylex()
*** 2557,2561 ****
                s += 2;
                d = s;
!               s = scan_word(s, tokenbuf, FALSE, &len);
                tmp = keyword(tokenbuf, len);
                if (tmp < 0)
- - --- 2563,2567 ----
                s += 2;
                d = s;
!               s = scan_word(s, tokenbuf, sizeof tokenbuf, FALSE, &len);
                tmp = keyword(tokenbuf, len);
                if (tmp < 0)
*************** yylex()
*** 3244,3250 ****

            if (isIDFIRST(*s) || *s == '\'' || *s == ':') {
!               char tmpbuf[128];
                expect = XBLOCK;
!               d = scan_word(s, tmpbuf, TRUE, &len);
                if (strchr(tmpbuf, ':'))
                    sv_setpv(subname, tmpbuf);
- - --- 3250,3256 ----

            if (isIDFIRST(*s) || *s == '\'' || *s == ':') {
!               char tmpbuf[sizeof tokenbuf];
                expect = XBLOCK;
!               d = scan_word(s, tmpbuf, sizeof tmpbuf, TRUE, &len);
                if (strchr(tmpbuf, ':'))
                    sv_setpv(subname, tmpbuf);
*************** char *what;
*** 4091,4102 ****

  static char *
! scan_word(s, dest, allow_package, slp)
  register char *s;
  char *dest;
  int allow_package;
  STRLEN *slp;
  {
      register char *d = dest;
      for (;;) {
        if (isALNUM(*s))
            *d++ = *s++;
- - --- 4097,4112 ----

  static char *
! scan_word(s, dest, destlen, allow_package, slp)
  register char *s;
  char *dest;
+ STRLEN destlen;
  int allow_package;
  STRLEN *slp;
  {
      register char *d = dest;
+     register char *e = d + destlen - 3;  /* two-character token, ending NUL
*/
      for (;;) {
+       if (d >= e)
+           croak(too_long);
        if (isALNUM(*s))
            *d++ = *s++;
*************** STRLEN *slp;
*** 4119,4129 ****

  static char *
! scan_ident(s,send,dest,ck_uni)
  register char *s;
  register char *send;
  char *dest;
  I32 ck_uni;
  {
      register char *d;
      char *bracket = 0;
      char funny = *s++;
- - --- 4129,4141 ----

  static char *
! scan_ident(s, send, dest, destlen, ck_uni)
  register char *s;
  register char *send;
  char *dest;
+ STRLEN destlen;
  I32 ck_uni;
  {
      register char *d;
+     register char *e;
      char *bracket = 0;
      char funny = *s++;
*************** I32 ck_uni;
*** 4134,4143 ****
        s = skipspace(s);
      d = dest;
      if (isDIGIT(*s)) {
!       while (isDIGIT(*s))
            *d++ = *s++;
      }
      else {
        for (;;) {
            if (isALNUM(*s))
                *d++ = *s++;
- - --- 4146,4161 ----
        s = skipspace(s);
      d = dest;
+     e = d + destlen - 3;      /* two-character token, ending NUL */
      if (isDIGIT(*s)) {
!       while (isDIGIT(*s)) {
!           if (d >= e)
!               croak(too_long);
            *d++ = *s++;
+       }
      }
      else {
        for (;;) {
+           if (d >= e)
+               croak(too_long);
            if (isALNUM(*s))
                *d++ = *s++;

- ---------------------------------------------------------------------------

End of patch.

- ------------------------------------------------------------------------------

[ End CERT Advisory ]

[ Append Silicon Graphic Inc. Advisory ]

-----BEGIN PGP SIGNED MESSAGE-----

______________________________________________________________________________
                Silicon Graphics Inc. Security Advisory

        Title:   Buffer Overflow Vulnerability in suidperl/sperl program
        Title:   CERT CA-97.17 and AUSCERT AA-97.13
        Number:  19980404-01-I
        Date:    April 6, 1998
______________________________________________________________________________

Silicon Graphics provides this information freely to the SGI user community
for its consideration, interpretation, implementation and use.   Silicon
Graphics recommends that this information be acted upon as soon as possible.

Silicon Graphics provides the information in this Security Advisory on
an "AS-IS" basis only, and disclaims all warranties with respect thereto,
express, implied or otherwise, including, without limitation, any warranty
of merchantability or fitness for a particular purpose.  In no event shall
Silicon Graphics be liable for any loss of profits, loss of business, loss
of data or for any indirect, special, exemplary, incidental or consequential
damages of any kind arising from your use of, failure to use or improper
use of any of the instructions or information in this Security Advisory.
______________________________________________________________________________


- -----------------------
- --- Issue Specifics ---
- -----------------------

The suidperl or sperl program is an altered versions of PERL which allows
PERL scripts to be run under the setuid of a particular user.

Unfortunately, a buffer overrun has been discovered in the suidperl/sperl
program which could allow arbitrary commands to be run as the
privileged user root.

Silicon Graphics Inc. has investigated the issue and recommends the
following steps for neutralizing the exposure.  It is HIGHLY RECOMMENDED
that these measures be implemented on ALL vulnerable SGI systems.


- --------------
- --- Impact ---
- --------------

As a service to its customers, Silicon Graphics provides IRIX installable
inst images of many popular "free" software packages and can be found
on the SGI Freeware 1.0/2.0 CD or online at:

http://www.sgi.com/TasteOfDT/public/freeware.html

The suidperl/sperl program is freeware and is not installed by default.

Versions 5.003 and lower of suidperl/sperl have this buffer overrun
vulnerability.

With a local account, the suidperl/sperl buffer overrun vulnerability can be
exploited locally and remotely.

The suidperl/sperl buffer overrun vulnerability can be utilized to execute
commands with root privileges.

The suidperl/sperl buffer overrun vulnerability has been publicly discussed
in Usenet newsgroups and mailing lists and also reported in CERT Advisory
CA-97.17 and AUSCERT Advisory AA-97.13.


- --------------------------
- --- Temporary Solution ---
- --------------------------

Although new releases of suidperl/sperl are available to fix this issue, it
is realized that there may be situations where installing the new release
immediately may not be possible.

To determine if a system is vulnerable to this problem and to disable
the programs that are believed to be vulnerable, use the following steps.

     1) Become the root user on the system.

                % /bin/su -
                Password:
                #

     2) Find suidperl or sperl programs and disable them.

        You will need to run the find(1) command on each system you
        maintain because the command examines files on local disks only.

        Note that this is one long command, though we have separated it
        onto five lines using backslashes.

                # find / -local -type f -user root \
                  \( -name 'sperl4.[0-9][0-9][0-9]' \
                  -o -name 'sperl5.00[0-3]' \
                  -o -name 'suidperl' \) \
                  -perm -04000 -print -ok chmod ug-s '{}' \;

        This command will find all files on a system that are
        - only in the file system you name (/ -local)
        - regular files (-type f)
        - owned by root (-user root)
        - named appropriately (-name 'sperl4.[0-9][0-9][0-9]' -o -name
          'sperl5.00[0-3]' -o -name 'suidperl')
        - setuid root (-perm -04000)

        Once found, those files will
        - have their names printed (-print)
        - have their modes changed, but only if you type `y' in response
          to the prompt (-ok chmod ug-s '{}' \;)

        After you have run this command on all your systems, they will no
        longer be vulnerable. Note that after disabling the suidperl and sperl
        programs, they will no longer be able to emulate the set-user-ID and
        set-group-ID features of the kernel.

     3) Return to previous level.

                # exit
                $


- ----------------
- --- Solution ---
- ----------------

No Silicon Graphic's patches are available for freeware software.
As freeware software, all reasonable efforts will be made to address
the issue in future releases of the Silicon Graphic's Freeware.

Unsupported patches are publicly available from http://www.perl.com/


- ------------------------
- --- Acknowledgments ---
- ------------------------

Silicon Graphics wishes to thank the Internet Community, CERT Coordination
Center, and AUSCERT for their assistance in this matter.


- -----------------------------------------------------------
- --- Silicon Graphics Inc. Security Information/Contacts ---
- -----------------------------------------------------------

If there are questions about this document, email can be sent to
cse-security-alert@sgi.com.

                      ------oOo------

Silicon Graphics provides security information and patches for
use by the entire SGI community.  This information is freely
available to any person needing the information and is available
via anonymous FTP and the Web.

The primary SGI anonymous FTP site for security information and patches
is sgigate.sgi.com (204.94.209.1).  Security information and patches
are located under the directories ~ftp/security and ~ftp/patches,
respectively. The Silicon Graphics Security Headquarters Web page is
accessible at the URL http://www.sgi.com/Support/security/security.html.

For issues with the patches on the FTP sites, email can be sent to
cse-security-alert@sgi.com.

For assistance obtaining or working with security patches, please
contact your SGI support provider.

                      ------oOo------

Silicon Graphics provides a free security mailing list service
called wiretap and encourages interested parties to self-subscribe
to receive (via email) all SGI Security Advisories when they are
released. Subscribing to the mailing list can be done via the Web
(http://www.sgi.com/Support/security/wiretap.html) or by sending email
to SGI as outlined below.

% mail wiretap-request@sgi.com
subscribe wiretap <YourEmailAddress>
end
^d

In the example above, <YourEmailAddress> is the email address that you
wish the mailing list information sent to.  The word end must be on a
separate line to indicate the end of the body of the message. The
control-d (^d) is used to indicate to the mail program that you are
finished composing the mail message.


                      ------oOo------

Silicon Graphics provides a comprehensive customer World Wide Web site.
This site is located at http://www.sgi.com/Support/security/security.html.

                      ------oOo------

For reporting *NEW* SGI security issues, email can be sent to
security-alert@sgi.com or contact your SGI support provider.  A
support contract is not required for submitting a security report.

______________________________________________________________________________
  This information is provided freely to all interested parties and may
  be redistributed provided that it is not altered in any way, Silicon
  Graphics is appropriately credited and the document retains and
  includes its valid PGP signature.

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Version: 2.6.2

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-----END PGP SIGNATURE-----

[ End Silicon Graphic Inc. Advisory ]

______________________________________________________________________________

CIAC wishes to acknowledge the contributions of CERT, Chip Salzenberg, Larry
Wall, and Warner Losh for the information contained in this bulletin.
______________________________________________________________________________

CIAC, the Computer Incident Advisory Capability, is the computer
security incident response team for the U.S. Department of Energy
(DOE) and the emergency backup response team for the National
Institutes of Health (NIH). CIAC is located at the Lawrence Livermore
National Laboratory in Livermore, California. CIAC is also a founding
member of FIRST, the Forum of Incident Response and Security Teams, a
global organization established to foster cooperation and coordination
among computer security teams worldwide.

CIAC services are available to DOE, DOE contractors, and the NIH. CIAC
can be contacted at:
    Voice:    +1 510-422-8193
    FAX:      +1 510-423-8002
    STU-III:  +1 510-423-2604
    E-mail:   ciac@llnl.gov

For emergencies and off-hour assistance, DOE, DOE contractor sites,
and the NIH may contact CIAC 24-hours a day. During off hours (5PM -
8AM PST), call the CIAC voice number 510-422-8193 and leave a message,
or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two
Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC
duty person, and the secondary PIN number, 8550074 is for the CIAC
Project Leader.

Previous CIAC notices, anti-virus software, and other information are
available from the CIAC Computer Security Archive.

   World Wide Web:      http://ciac.llnl.gov/
   Anonymous FTP:       ciac.llnl.gov (198.128.39.53)
   Modem access:        +1 (510) 423-4753 (28.8K baud)
                        +1 (510) 423-3331 (28.8K baud)

CIAC has several self-subscribing mailing lists for electronic
publications:
1. CIAC-BULLETIN for Advisories, highest priority - time critical
   information and Bulletins, important computer security information;
2. CIAC-NOTES for Notes, a collection of computer security articles;
3. SPI-ANNOUNCE for official news about Security Profile Inspector
   (SPI) software updates, new features, distribution and
   availability;
4. SPI-NOTES, for discussion of problems and solutions regarding the
   use of SPI products.

Our mailing lists are managed by a public domain software package
called Majordomo, which ignores E-mail header subject lines. To
subscribe (add yourself) to one of our mailing lists, send the
following request as the E-mail message body, substituting
ciac-bulletin, ciac-notes, spi-announce OR spi-notes for list-name:

E-mail to       ciac-listproc@llnl.gov or majordomo@tholia.llnl.gov:
        subscribe list-name
  e.g., subscribe ciac-notes

You will receive an acknowledgment email immediately with a confirmation
that you will need to mail back to the addresses above, as per the
instructions in the email.  This is a partial protection to make sure
you are really the one who asked to be signed up for the list in question.

If you include the word 'help' in the body of an email to the above address,
it will also send back an information file on how to subscribe/unsubscribe,
get past issues of CIAC bulletins via email, etc.

PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing
communities receive CIAC bulletins.  If you are not part of these
communities, please contact your agency's response team to report
incidents. Your agency's team will coordinate with CIAC. The Forum of
Incident Response and Security Teams (FIRST) is a world-wide
organization. A list of FIRST member organizations and their
constituencies can be obtained via WWW at http://www.first.org/.

This document was prepared as an account of work sponsored by an
agency of the United States Government. Neither the United States
Government nor the University of California nor any of their
employees, makes any warranty, express or implied, or assumes any
legal liability or responsibility for the accuracy, completeness, or
usefulness of any information, apparatus, product, or process
disclosed, or represents that its use would not infringe privately
owned rights. Reference herein to any specific commercial products,
process, or service by trade name, trademark, manufacturer, or
otherwise, does not necessarily constitute or imply its endorsement,
recommendation or favoring by the United States Government or the
University of California. The views and opinions of authors expressed
herein do not necessarily state or reflect those of the United States
Government or the University of California, and shall not be used for
advertising or product endorsement purposes.

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