PR08-01: Several XSS, a cross-domain redirect and a webroot disclosure
on Spyce - Python Server Pages (PSP)
Vulnerability found: 19th December 2007
Vendor informed: 14th January 2007
Vulnerability fixed: the vendor did not respond, however a workaround
has been included in the "Fix" section of this advisory.
All Spyce sample scripts that return client-supplied input back to the
browser are vulnerable to XSS. It is also possible to redirect users to
third-party sites and obtain the webroot path by not submitting required
parameters to certain scripts.
Note: tested on Spyce - Python Server Pages version 2.1.3
The following are only some examples that demonstrate XSS:
Other vulnerable scripts and unsanitized parameters:
Note: some XSS can only be exploited via POST requests (as opposed to
GET). This could be done by using an embedded HTML form with
to auto-submits itself. Such form would be located on a third-party site.
Cross-domain redirect PoC:
Requesting the following URL returns the server's webroot:
An attacker may be able to cause execution of malicious scripting code
in the browser of a user who clicks on a link to a Spyce-based site.
Such code would run within the security context of the target domain.
This type of attack can result in non-persistent defacement of the
target site, or the redirection of confidential information (i.e.:
session IDs) to unauthorised third parties.
Attackers can redirect victim users to third-party sites. Such behaviour
can help attackers perform phishing attacks by redirecting the victim to
a spoof login page.
Remove sample scripts from live environments.
Credits: Richard Brain, Jan Fry, and Bruno Kovacs of ProCheckUp Ltd
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