Debian: DSA-3105-1 Critical Heirloom Mailx Command Execution Risk

Two security vulnerabilities were discovered in Heirloom mailx, an
implementation of the "mail" command:

CVE-2004-2771

mailx interprets 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 invoke
"mail -t" or "sendmail -i -t" instead, passing the recipient addresses
as part of the mail header.

For the stable distribution (wheezy), these problems have been fixed in
version 12.5-2+deb7u1.

We recommend that you upgrade your heirloom-mailx packages.

Further information abo...