Gentoo: Hashcash Format string vulnerability
Posted by Benjamin D. Thomas   
Gentoo A format string vulnerability in the Hashcash utility could allow an attacker to execute arbitrary code.
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Gentoo Linux Security Advisory                           GLSA 200503-12
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: Hashcash: Format string vulnerability
      Date: March 06, 2005
      Bugs: #83541
        ID: 200503-12

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Synopsis
========

A format string vulnerability in the Hashcash utility could allow an
attacker to execute arbitrary code.

Background
==========

Hashcash is a utility for generating Hashcash tokens, a proof-of-work
system to reduce the impact of spam.

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

    -------------------------------------------------------------------
     Package            /  Vulnerable  /                    Unaffected
    -------------------------------------------------------------------
  1  net-misc/hashcash      < 1.16-r1                       >= 1.16-r1

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

Tavis Ormandy of the Gentoo Linux Security Audit Team identified a flaw
in the Hashcash utility that an attacker could expose by specifying a
malformed reply address.

Impact
======

Successful exploitation would permit an attacker to disrupt Hashcash
users, and potentially execute arbitrary code.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Hashcash users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-misc/hashcash-1.16-r1"

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

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

  http://security.gentoo.org/glsa/glsa-200503-12.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 2005 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