SynopsisThe remote Debian host is missing a security-related update.
DescriptionTwo security vulnerabilities were discovered in Heirloom mailx, an implementation of the 'mail' command :
- CVE-2004-2771 mailx interprets shell meta-characters in certain email addresses.
- CVE-2014-7844 An unexpected feature of mailx treats syntactically valid email addresses as shell commands to execute.
Shell command execution can be re-enabled using the 'expandaddr'option.
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 invokemail -t or sendmail -i -t instead, passing the recipient addresses as part of the mail header.
SolutionUpgrade the heirloom-mailx packages.
For the stable distribution (wheezy), these problems have been fixed in version 12.5-2+deb7u1.