What’s Vulnerable › Vulnerabilities

CVE-2020-15179: HTML Injection in ScratchSig

• Severity: critical (CVSS 9.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-09-15 · updated 2026-06-17
• Weakness: CWE-79

Description

The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting. Using <script> tag inside <scratchsig> tag, attackers with edit permission can execute scripts on visitors' browser. With MediaWiki JavaScript API, this can potentially lead to privilege escalation and/or account takeover. This has been patched in release 1.0.1. This has already been deployed to all Scratch Wikis. No workarounds exist other than disabling the extension completely.

Affected products

• InternationalScratchWiki wiki-scratchsig: before 1.0.1 — fixed in 1.0.1

How to fix

Upgrade to a fixed version: InternationalScratchWiki wiki-scratchsig 1.0.1. Check the vendor advisory for mitigations.

References

• https://github.com/InternationalScratchWiki/wiki-scratchsig/commit/4160a39a20eebeb63a59eb7597a91b961eca6388
• https://github.com/InternationalScratchWiki/wiki-scratchsig/security/advisories/GHSA-gp9v-pg9f-vmp6
• https://github.com/InternationalScratchWiki/wiki-scratchsig/commit/4160a39a20eebeb63a59eb7597a91b961eca6388
• https://github.com/InternationalScratchWiki/wiki-scratchsig/security/advisories/GHSA-gp9v-pg9f-vmp6

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