CVE-2020-17354Public exploit

Code execution via exposed output-definition Scheme functions

Published Apr 15, 2023 · Updated Feb 6, 2025

Sandbox escape in LilyPond before 2.24 allows attackers to execute arbitrary code when a crafted .ly file is converted. The safe-mode allowlist exposes output-def-scope and output-def-lookup, which reach a parser-created Guile module that inherits the system command binding. Exploitation requires processing attacker-controlled input with -dsafe; commands run with the LilyPond process's privileges and can read, alter, or disrupt host resources.

CVSS severity8.6
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sandbox escape in LilyPond before 2.24 allows attackers to execute arbitrary code when a crafted .ly file is converted. The safe-mode allowlist exposes output-def-scope and output-def-lookup, which reach a parser-created Guile module that inherits the system command binding. Exploitation requires processing attacker-controlled input with -dsafe; commands run with the LilyPond process's privileges and can read, alter, or disrupt host resources.

The record

CVE
CVE-2020-17354
Published
Apr 15, 2023
Updated
Feb 6, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-863, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.6NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
8.6CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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