Arch Linux Security Advisory ASA-201910-13
=========================================
Severity: High
Date    : 2019-10-23
CVE-ID  : CVE-2019-18182 CVE-2019-18183
Package : pacman
Type    : arbitrary command execution
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1049

Summary
======
The package pacman before version 5.2.0-1 is vulnerable to arbitrary
command execution.

Resolution
=========
Upgrade to 5.2.0-1.

# pacman -Syu "pacman>=5.2.0-1"

The problems have been fixed upstream in version 5.2.0.

Workaround
=========
For CVE-2019-18182:
    Ensure `XferCommand` is commented out in `/etc/pacman.conf`

For CVE-2019-18183:
    Ensure `UseDelta` is commented out in `/etc/pacman.conf`

Description
==========
- CVE-2019-18182 (arbitrary command execution)

pacman before 5.2 is vulnerable to arbitrary command injection in
src/pacman/conf.c in the download_with_xfercommand() function. This can
be exploited when unsigned databases are used. To exploit the
vulnerability, the user must enable a non-default XferCommand and
retrieve an attacker-controlled crafted database and package.

- CVE-2019-18183 (arbitrary command execution)

pacman before 5.2 is vulnerable to arbitrary command injection in
lib/libalpm/sync.c in the apply_deltas() function. This can be
exploited when unsigned databases are used. To exploit the
vulnerability, the user must enable the non-default delta feature and
retrieve an attacker-controlled crafted database and delta file.

Impact
=====
A remote attacker is able to execute arbitrary commands on the host
with a specially crafted database and a package or delta file.

References
=========
https://gitlab.archlinux.org/explore/groups
https://gitlab.archlinux.org/explore/groups
https://gitlab.archlinux.org/explore/groups
https://gitlab.archlinux.org/explore/groups
https://security.archlinux.org/CVE-2019-18182
https://security.archlinux.org/CVE-2019-18183