Ubuntu 10.04 LTS / 12.04 LTS / 14.04 LTS / 14.10 : bsd-mailx vulnerability (USN-2455-1)
High Nessus Plugin ID 80413
SynopsisThe remote Ubuntu host is missing a security-related patch.
DescriptionIt was discovered that bsd-mailx contained a feature that allowed syntactically valid email addresses to be treated as shell commands. A remote attacker could possibly use this issue with a valid email address to execute arbitrary commands.
This functionality has now been disabled by default, and can be re-enabled with the 'expandaddr' configuration option. This update alone does not remove all possibilities of command execution. In environments where scripts use mailx to process arbitrary email addresses, it is recommended to modify them to use a '--' separator before the address to properly handle those that begin with '-'.
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected bsd-mailx package.