Cross-origin information disclosure via MediaError messages
Published Feb 26, 2021 · Updated Aug 3, 2024
Cross-origin information disclosure in Firefox before 86 and Firefox ESR or Thunderbird before 78.8 exposes media details to remote attackers. The media decoder propagated detailed CORS-cross-origin decoding failures into the script-readable MediaError.message property instead of replacing them with a default string. Exploitation requires interaction with attacker-controlled content that loads cross-origin audio or video; ordinary Thunderbird email reading disables scripting, and the flaw only discloses resource or response details.
Summary
What happened
Cross-origin information disclosure in Firefox before 86 and Firefox ESR or Thunderbird before 78.8 exposes media details to remote attackers. The media decoder propagated detailed CORS-cross-origin decoding failures into the script-readable MediaError.message property instead of replacing them with a default string. Exploitation requires interaction with attacker-controlled content that loads cross-origin audio or video; ordinary Thunderbird email reading disables scripting, and the flaw only discloses resource or response details.
The record
- CVE
- CVE-2021-23973
- Published
- Feb 26, 2021
- Updated
- Aug 3, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-209
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 26, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 86
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
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Your stack
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