Subject: [ASA-201908-14] gettext: arbitrary code execution

Arch Linux Security Advisory ASA-201908-14
==========================================

Severity: High
Date    : 2019-08-24
CVE-ID  : CVE-2018-18751
Package : gettext
Type    : arbitrary code execution
Remote  : Yes
Link    : https://security.archlinux.org/AVG-885

Summary
=======

The package gettext before version 0.20.1-1 is vulnerable to arbitrary
code execution.

Resolution
==========

Upgrade to 0.20.1-1.

# pacman -Syu "gettext>=0.20.1-1"

The problem has been fixed upstream in version 0.20.1.

Workaround
==========

None.

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

An issue was discovered in GNU gettext 0.19.8. There is a double free
in default_add_message in read-catalog.c, related to an invalid free in
po_gram_parse in po-gram-gen.y, as demonstrated by lt-msgfmt.

Impact
======

A local attacker is able to execute arbitrary code by using a specially
crafted message.

References
==========

https://github.com/CCCCCrash/POCs/tree/master/Bin/Tools-gettext-0.19.8.1/heapcorruption
https://github.com/CCCCCrash/POCs/tree/master/Bin/Tools-gettext-0.19.8.1/doublefree
https://git.savannah.gnu.org/gitweb/?p=gettext.git;a=commitdiff;h=dce3a16
https://security.archlinux.org/CVE-2018-18751