GLSA 200603-07 flex: Potential insecure code generation
Posted on: 03/10/2006 11:22 PM

A new security update has been released for Gentoo Linux - flex: Potential insecure code generation. Here the announcement:

Gentoo Linux Security Advisory GLSA 200603-07
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http://security.gentoo.org/
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Severity: Normal
Title: flex: Potential insecure code generation
Date: March 10, 2006
Bugs: #122940
ID: 200603-07

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Synopsis
========

flex might generate code with a buffer overflow, making applications
using such scanners vulnerable to the execution of arbitrary code.

Background
==========

flex is a programming tool used to generate scanners (programs which
recognize lexical patterns in text).

Affected packages
=================

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 sys-devel/flex lt; 2.5.33-r1 gt;= 2.5.33-r1

Description
===========

Chris Moore discovered a buffer overflow in a special class of
lexicographical scanners generated by flex. Only scanners generated by
grammars which use either REJECT, or rules with a "variable trailing
context" might be at risk.

Impact
======

An attacker could feed malicious input to an application making use of
an affected scanner and trigger the buffer overflow, potentially
resulting in the execution of arbitrary code.

Workaround
==========

Avoid using vulnerable grammar in your flex scanners.

Resolution
==========

All flex users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=sys-devel/flex-2.5.33-r1"

References
==========

[ 1 ] CVE-2006-0459
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-0459

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

http://security.gentoo.org/glsa/glsa-200603-07.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2006 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.0



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