Sensitive URL disclosure via CSP redirect reports
Published Feb 26, 2021 · Updated Aug 3, 2024
Information disclosure in Mozilla Firefox before 86, Firefox ESR before 78.8, and Thunderbird before 78.8 exposes redirect URLs to attackers. Blocked frame navigation records the post-redirect destination, rather than the original frame URI, as the blocked URI in a CSP violation report. A user must load an attacker-controlled page that frames a redirecting resource; the report can reveal URL paths, usernames, OAuth codes, or access tokens.
Summary
What happened
Information disclosure in Mozilla Firefox before 86, Firefox ESR before 78.8, and Thunderbird before 78.8 exposes redirect URLs to attackers. Blocked frame navigation records the post-redirect destination, rather than the original frame URI, as the blocked URI in a CSP violation report. A user must load an attacker-controlled page that frames a redirecting resource; the report can reveal URL paths, usernames, OAuth codes, or access tokens.
The record
- CVE
- CVE-2021-23968
- Published
- Feb 26, 2021
- Updated
- Aug 3, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-200, T1528
- 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?
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 Bugzilla redirect-path disclosure reproductionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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