Peter Winter-Smith of NGSSoftware has discovered a high risk vulnerability
in the Microsoft Windows Remote Access Connection Manager (RASMAN) service
which (under certain versions of the OS) can allow a remote, anonymous
attacker to gain complete control over a vulnerable system.
The vulnerability is specific to one of the RPC interfaces provided by the
RASMAN service. A sequence of specially crafted RPC calls to a given
function exposed through the interface can lead to registry corruption,
which can - in turn - lead to stack memory corruption within the Service
Host instance hosting the RASMAN service.
Under a default install of Windows 2000 SP4 the vulnerability can be reached
by an anonymous user, under Windows XP SP2 and Windows 2003 Server the
vulnerability can only be used for local privilege elevation.
This issue has been resolved in the Microsoft security bulletin MS06-025
which can be downloaded from:
NGSSoftware are going to withhold details of this flaw for three months.
Full details will be published on the 13th September 2006. This three month
window will allow users of Microsoft Windows the time needed to apply the
patch before the details are released to the general public. This reflects
NGSSoftware's approach to responsible disclosure.
NGSSoftware Insight Security Research
+44(0)208 401 0070