- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 200603-08 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - http://security.gentoo.org/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Severity: Normal Title: GnuPG: Incorrect signature verification Date: March 10, 2006 Bugs: #125217 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 ------------------------------------------------------------------- 1 app-crypt/gnupg < 1.4.2.2 >= 1.4.2.2 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 ========== [ 1 ] CVE-2006-0049 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-0049 [ 2 ] GnuPG Announcement http://lists.gnupg.org/pipermail/gnupg-announce/2006q1/000216.html Availability ============ This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200603-08.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 (at) gentoo (dot) org [email concealed] 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEEfCovcL1obalX08RAsedAJwP8hBZ4wfWjhFZGNjHqLVMRpORRQCeIQOc pWoHSkWEg/j6hiIA8LLEBbE= =SwCF -----END PGP SIGNATURE-----