CVE-2019-18183

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-02-24 · updated 2026-06-17
Weakness: CWE-78

Description

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.

Affected products

Fedoraproject Fedora: 30, 31, 32
Pacman Project Pacman: before 5.2 — fixed in 5.2

How to fix

Upgrade to a fixed version: Pacman Project Pacman 5.2. Check the vendor advisory for mitigations.

References

https://git.archlinux.org/pacman.git/commit/?id=c0e9be7973be6c81b22fde91516fb8991e7bb07b
https://git.archlinux.org/pacman.git/tree/lib/libalpm/sync.c?h=v5.1.3#n767
https://github.com/alpinelinux/alpine-secdb/blob/master/v3.11/community.yaml
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2TTUXXUW5OCOASIRMJK4RHEPLEA33Y6C/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K53C45EDWBU3UCN3IRIGR5EZUNWXS7BW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KIDJ4XKBZRRVRFFGKUA3ZU6NFIP5JUG3/
https://git.archlinux.org/pacman.git/commit/?id=c0e9be7973be6c81b22fde91516fb8991e7bb07b
https://git.archlinux.org/pacman.git/tree/lib/libalpm/sync.c?h=v5.1.3#n767
https://github.com/alpinelinux/alpine-secdb/blob/master/v3.11/community.yaml
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2TTUXXUW5OCOASIRMJK4RHEPLEA33Y6C/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K53C45EDWBU3UCN3IRIGR5EZUNWXS7BW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KIDJ4XKBZRRVRFFGKUA3ZU6NFIP5JUG3/

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