Subject: [ASA-201711-39] procmail: arbitrary code execution

Arch Linux Security Advisory ASA-201711-39
==========================================

Severity: Critical
Date    : 2017-11-30
CVE-ID  : CVE-2017-16844
Package : procmail
Type    : arbitrary code execution
Remote  : Yes
Link    : https://security.archlinux.org/AVG-515

Summary
=======

The package procmail before version 3.22-9 is vulnerable to arbitrary
code execution.

Resolution
==========

Upgrade to 3.22-9.

# pacman -Syu "procmail>=3.22-9"

The problem has been fixed upstream but no release is available yet.

Workaround
==========

None.

Description
===========

A heap-based buffer overflow flaw was found in the loadbuf function in
formisc.c in the formail utility in procmail <= 3.22 because of a
hardcoded realloc size. When the buffer is too small, the function
tries to resize it, but only by Bsize (=128) bytes which is not
necessarily enough. A remote attacker could send a specially crafted
email that, when processed by formail, could cause formail to crash or,
possibly, execute arbitrary code as the user running formail.

Impact
======

A remote attacker could send a specially crafted email that, when
processed by formail, could cause formail to crash or, possibly,
execute arbitrary code as the user running formail.

References
==========

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=876511
https://security.archlinux.org/CVE-2017-16844