GnuPG: User-assisted execution of arbitrary code

Background

The GNU Privacy Guard, GnuPG, is a free replacement for the PGP suite of cryptographic software. The GPGSM utility in GnuPG is responsible for processing X.509 certificates, signatures and encryption as well as S/MIME messages.

Description

The GPGSM utility in GnuPG contains a use-after-free vulnerability that may be exploited when importing a crafted X.509 certificate explicitly or during the signature verification process.

Impact

An unauthenticated remote attacker may execute arbitrary code with the privileges of the user running GnuPG by enticing them to import a crafted certificate.

Workaround

There is no known workaround at this time.

Resolution

All GnuPG 2.x users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-crypt/gnupg-2.0.16-r1"