GLSA 200603-08: GnuPG: Incorrect signature verification
| Severity: | normal |
| Title: | GnuPG: Incorrect signature verification |
| Date: | 03/10/2006 |
| Bugs: | |
| ID: | 200603-08 |
Synopsis
GnuPG may erroneously report a modified or unsigned message has a valid digital signature.Background
The GNU Privacy Guard, GnuPG, is a free replacement for the PGP suite of cryptographic software that may be used without restriction, as it does not rely on any patented algorithms. GnuPG can be used to digitally sign messages, a method of ensuring the authenticity of a message using public key cryptography.
Affected packages
| Package | Vulnerable | Unaffected | Architecture(s) |
|---|---|---|---|
| app-crypt/gnupg | < 1.4.2.2 | >= 1.4.2.2 | All supported architectures |
Description
OpenPGP is the standard that defines the format of digital signatures supported by GnuPG. OpenPGP signatures consist of multiple sections, in a strictly defined order. Tavis Ormandy of the Gentoo Linux Security Audit Team discovered that certain illegal signature formats could allow signed data to be modified without detection. GnuPG has previously attempted to be lenient when processing malformed or legacy signature formats, but this has now been found to be insecure.
Impact
A remote attacker may be able to construct or modify a digitally-signed message, potentially allowing them to bypass authentication systems, or impersonate another user.
Workaround
There is no known workaround at this time.
Resolution
All GnuPG users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-crypt/gnupg-1.4.2.2"
References
Availability
This GLSA and any updates to it are available for viewing at the Gentoo Security Website:
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 https://bugs.gentoo.org.
License
Copyright 2010 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.