SynopsisThe remote Debian host is missing a security update.
DescriptionIt was discovered that bsd-mailx, an implementation of the 'mail' command, had an undocumented feature which treats syntactically valid email addresses as shell commands to execute.
Users who need this feature can re-enable it using the 'expandaddr' in an appropriate mailrc file. This update also removes the obsolete -T option. An older security vulnerability, CVE-2004-2771, had already been addressed in the Debian's bsd-mailx package.
Note that this security update does not remove all mailx facilities for command execution, though. Scripts which send mail to addresses obtained from an untrusted source (such as a web form) should use the '--' separator before the email addresses (which was fixed to work properly in this update), or they should be changed to invoke 'mail
-t' or 'sendmail -i -t' instead, passing the recipient addresses as part of the mail header.
For the oldstable distribution (squeeze), this problem has been fixed in version 8.1.2-0.20100314cvs-1+deb6u1.
We recommend that you upgrade your bsd-mailx packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected bsd-mailx package.