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 Ghostscript, multiple arbitrary code execution vulnerabilities
 May 11, 2010
 CVE-2010-1869
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==Description==

Ghostscript (www.ghostscript.com), an interpreter for the PostScript language,
is vulnerable to two memory corruption vulnerabilities:

1. A stack overflow in the parser for Ghostscript versions 8.64 and 8.70 occurs
when very long identifiers are provided within a PostScript file.  By enticing
a user to open a maliciously crafted PostScript file, arbitrary code execution
can be achieved.  This vulnerability was reported to downstream distributions
by me on March 4, 2010.  An anonymous researcher independently published this
vulnerability today (May 11, 2010), prompting this advisory.  This issue has
been assigned CVE-2010-1869.

2. GhostScript (all tested versions) fails to properly handle infinitely
recursive procedure invocations.  By providing a PostScript file with a
sequence such as:

/A{pop 0 A 0} bind def
/product A 0

the interpreter's internal stack will be overflowed with recursive calls, at
which point execution will jump to an attacker-controlled address.  This
vulnerability can be exploited by enticing a user to open a maliciously crafted
PostScript file, achieving arbitrary code execution.  This issue has not yet
been assigned a CVE identifier.

==Solution==

In the absence of a patch, users are encouraged to discontinue use of
Ghostscript or avoid processing untrusted PostScript files.

==Credits==

These vulnerabilities were discovered by Dan Rosenberg
(dan.j.rosenberg@gmail.com).

==Timeline==

3/04/10 - Initial report to downstream distribution
5/11/10 - Anonymous researcher discloses first issue
5/11/10 - Disclosure

==References==

CVE identifier CVE-2010-1869 has been assigned to the first issue.

The original report for this bug can be found at:
https://bugs.launchpad.net/ubuntu/+source/ghostscript/+bug/546009

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