Hashcash: Possible heap overflow — GLSA 200606-25

A heap overflow vulnerability in the Hashcash utility could allow an attacker to execute arbitrary code.

Affected Packages

net-misc/hashcash on all architectures
Affected versions < 1.21
Unaffected versions >= 1.21

Background

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

Description

Andreas Seltenreich has reported a possible heap overflow in the array_push() function in hashcash.c, as a result of an incorrect amount of allocated memory for the "ARRAY" structure.

Impact

By sending malicious entries to the Hashcash utility, an attacker may be able to cause an overflow, potentially resulting in the execution of arbitrary code with the privileges of the user running the application.

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-1.21"

References

Release Date
June 26, 2006

Latest Revision
July 29, 2006: 02

Severity
high

Exploitable
remote

Bugzilla entries