Parent-process memory corruption via unchecked WebAuthn extensions
Published Dec 22, 2022 · Updated Apr 15, 2025
Out-of-bounds write in Firefox before 99 and Firefox ESR or Thunderbird before 91.8 allows attackers to corrupt memory via WebAuthn data. WinWebAuthnManager::Register trusts an extension count from a compromised content process and iterates beyond a fixed stack array because release builds relied on a debug-only assertion instead of a runtime bounds check. A compromised content process and the Windows WebAuthn path are required; Thunderbird mail reading disables scripting, limiting ordinary email exposure.
Summary
What happened
Out-of-bounds write in Firefox before 99 and Firefox ESR or Thunderbird before 91.8 allows attackers to corrupt memory via WebAuthn data. WinWebAuthnManager::Register trusts an extension count from a compromised content process and iterates beyond a fixed stack array because release builds relied on a debug-only assertion instead of a runtime bounds check. A compromised content process and the Windows WebAuthn path are required; Thunderbird mail reading disables scripting, limiting ordinary email exposure.
The record
- CVE
- CVE-2022-28281
- Published
- Dec 22, 2022
- Updated
- Apr 15, 2025
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-787, T1068
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 22, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <99
What conditions does exploitation require?
What is affected?
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.
Public exploit references
- Mozilla Bugzilla trigger.htmlproof of concept · unverified
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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