Gentoo Logo

Hashcash: Format string vulnerability


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200503-12 / Hashcash
Release Date March 06, 2005
Latest Revision May 22, 2006: 02
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
net-misc/hashcash < 1.16-r1 >= 1.16-r1 All supported architectures

Related bugreports: #83541


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

2.  Impact Information


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


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.


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

3.  Resolution Information


There is no known workaround at this time.


All Hashcash users should upgrade to the latest version:

Code Listing 3.1: Resolution

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

4.  References


Page updated March 06, 2005

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.

Copyright 2001-2015 Gentoo Foundation, Inc. Questions, Comments? Contact us.