Arch Linux Security Advisory ASA-201705-14
=========================================
Severity: High
Date    : 2017-05-12
CVE-ID  : CVE-2017-8386
Package : git
Type    : access restriction bypass
Remote  : Yes
Link    : https://security.archlinux.org/AVG-267

Summary
======
The package git before version 2.13.0-1 is vulnerable to access
restriction bypass.

Resolution
=========
Upgrade to 2.13.0-1.

# pacman -Syu "git>=2.13.0-1"

The problem has been fixed upstream in version 2.13.0.

Workaround
=========
None.

Description
==========
A security issue has been found in git < 2.12.3, allowing a remote
restricted user to execute an interactive pager on the server by
causing it to spawn "git upload-pack --help". This is only an issue for
servers running the "git-shell" restricted login shell.

Impact
=====
A remote attacker can use the interactive pager commands to access and
modify arbitrary files on the affected host. If the login shell used is
not git-shell, a remote attacker might also be able to run arbitrary
commands on the affected host.

References
=========
https://lkml.iu.edu/hypermail/linux/kernel/1705.1/01337.html
https://git.kernel.org/pub/scm/git/git.git/commit/?id=3ec804490a265f4c418a321428c12f3f18b7eff5
https://insinuator.net/2017/05/git-shell-bypass-by-abusing-less-cve-2017-8386/
https://security.archlinux.org/CVE-2017-8386