Security readout for executives and security teams
Plain-English summary
CVE-2020-29007 affects MediaWiki sites using the Score extension through 0.3.0. A page editor could cause the server to run unintended code through the musical-score rendering path. If anonymous editing is enabled, exposure can extend to unauthenticated users. This is business-critical where public or broadly editable wikis use Score.
Executive priority
Treat this as urgent for any public or collaborative MediaWiki site using Score. The impact is full server compromise, and exposure may require only page-editing access. Prioritize inventory, disabling or updating Score, and reviewing edit permissions.
Technical view
The flaw is improper sandboxing around GNU LilyPond in MediaWiki Score, classified as CWE-94. The CVSS 3.1 score is 9.8 because exploitation is network-reachable, low-complexity, and can affect confidentiality, integrity, and availability. Sources describe arbitrary Scheme or shell code execution through crafted score content by users able to edit pages.
Likely exposure
Most likely exposed assets are MediaWiki installations with the Score extension enabled at version 0.3.0 or earlier, especially wikis allowing anonymous or low-trust page edits. Sites without Score enabled are not indicated as affected by the provided sources.
Exploitation context
The bundle does not show CISA KEV listing or confirm active exploitation in the wild. Public references include researcher material and a GitHub repository, so defenders should assume exploit details may be publicly accessible, but not claim observed exploitation without separate evidence.
Researcher notes
Evidence supports RCE in Score through 0.3.0 via LilyPond sandbox failure. Affected metadata in the bundle lacks precise CPEs, so asset validation must focus on MediaWiki extension inventory and configuration. Do not infer broader MediaWiki core exposure from these sources.
Mitigation direction
- Identify MediaWiki sites running the Score extension.
- Disable Score where it is not required.
- Apply the MediaWiki Score security advisory guidance.
- Upgrade to a vendor-supported non-affected Score version if available.
- Restrict page editing to trusted users until remediation is complete.
- Review anonymous editing settings on affected wikis.
Validation and detection
- Confirm Score extension version on each MediaWiki instance.
- Verify whether anonymous or low-trust users can edit pages.
- Check that the advisory remediation is applied in production.
- Review web and application logs for suspicious score-rendering activity.
- Confirm LilyPond execution is appropriately sandboxed per vendor guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-29007 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/seqred-s-a/cve-2020-29007CVE reference
- https://www.mediawiki.org/wiki/Extension:ScoreCVE reference
- https://phabricator.wikimedia.org/T257062CVE reference
- https://seqred.pl/en/cve-2020-29007-remote-code-execution-in-mediawiki-score/CVE reference
- https://www.mediawiki.org/wiki/Extension:Score/2021_security_advisoryCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Control of Generation of Code ('Code Injection')
Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.