Cross-origin information disclosure via Worker error differences
Published Dec 22, 2022 · Updated Apr 16, 2025
Information disclosure in Firefox before 97, Firefox ESR before 91.6, and Thunderbird before 91.6 lets remote attackers infer cross-origin MIME types. Web Worker importScripts returns distinct errors for valid JavaScript MIME types and invalid types or syntax, creating a content-type oracle. Exploitation requires interaction with attacker-controlled web content and reveals whether a targeted cross-origin resource is script content, not its body.
Summary
What happened
Information disclosure in Firefox before 97, Firefox ESR before 91.6, and Thunderbird before 91.6 lets remote attackers infer cross-origin MIME types. Web Worker importScripts returns distinct errors for valid JavaScript MIME types and invalid types or syntax, creating a content-type oracle. Exploitation requires interaction with attacker-controlled web content and reveals whether a targeted cross-origin resource is script content, not its body.
The record
- CVE
- CVE-2022-22760
- Published
- Dec 22, 2022
- Updated
- Apr 16, 2025
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-209
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 22, 2022CVE publishedPublication date reported by the CVE source.
- Apr 16, 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 <97
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.
Weakness, pattern, technique
Public exploit references
- Mozilla Bug 1740985 importScripts reproduction caseproof of concept · demonstrated
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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