CVE-2020-17354

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-04-15 · updated 2026-06-17
Weakness: CWE-863

Description

LilyPond before 2.24 allows attackers to bypass the -dsafe protection mechanism via output-def-lookup or output-def-scope, as demonstrated by dangerous Scheme code in a .ly file that causes arbitrary code execution during conversion to a different file format. NOTE: in 2.24 and later versions, safe mode is removed, and the product no longer tries to block code execution when external files are used.

Affected products

Lilypond: before 2.24.0 — fixed in 2.24.0

How to fix

Upgrade to a fixed version: Lilypond 2.24.0. Check the vendor advisory for mitigations.

References

http://lilypond.org/doc/v2.18/Documentation/usage/command_002dline-usage
https://gitlab.com/lilypond/lilypond/-/merge_requests/1522
https://lilypond.org/download.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K43PF6VGFJNNGAPY57BW3VMEFFOSMRLF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ST5BLLQ4GDME3SN7UE5OMNE5GZE66X4Y/
https://phabricator.wikimedia.org/T259210
https://tracker.debian.org/news/1249694/accepted-lilypond-2221-1-source-into-unstable/
https://www.mediawiki.org/wiki/Extension:Score/2021_security_advisory
http://lilypond.org/doc/v2.18/Documentation/usage/command_002dline-usage
https://gitlab.com/lilypond/lilypond/-/merge_requests/1522
https://lilypond.org/download.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K43PF6VGFJNNGAPY57BW3VMEFFOSMRLF/

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