14 DAY TRIAL // Canonical published details about GnuPG vulnerabilities for its Ubuntu 13.10, Ubuntu 13.04, Ubuntu 12.10, Ubuntu 12.04 LTS, and Ubuntu 10.04 LTS operating systems.
According to the company, GnuPG could expose sensitive information when performing decryption.
For example, it has been discovered that GnuPG was susceptible to an adaptive chosen ciphertext attack via acoustic emanations. A local attacker could have used this attack to possibly recover private keys.
For a more detailed description of the problems, you can visit Canonical's security notification.
Users can simply fix the security flaws by upgrading the operating systems to the latest gnupg2 and gnupg packages specific to each distribution.
A normal system update, executed with the Update Manager, will implement all the necessary changes. A complete system restart is not necessary to fix all the problems.