Sensitive URL disclosure via flawed CORS restrictions
Published Sep 8, 2021 · Updated Aug 3, 2024
Information disclosure in WebKit on iOS and iPadOS before 14.6 and macOS Big Sur before 11.4 allows attackers to leak sensitive redirect URLs. WebKit's CORS error handling returns the final cross-origin redirect URL to a fetch catch handler instead of withholding it. Exploitation requires malicious code execution and, when tracking protections apply, user interaction with attacker-controlled content; exposed URLs can contain OAuth or SSO tokens.
Summary
What happened
Information disclosure in WebKit on iOS and iPadOS before 14.6 and macOS Big Sur before 11.4 allows attackers to leak sensitive redirect URLs. WebKit's CORS error handling returns the final cross-origin redirect URL to a fetch catch handler instead of withholding it. Exploitation requires malicious code execution and, when tracking protections apply, user interaction with attacker-controlled content; exposed URLs can contain OAuth or SSO tokens.
The record
- CVE
- CVE-2021-30682
- Published
- Sep 8, 2021
- Updated
- Aug 3, 2024
- Vendor
- Apple
- Product
- iOS and iPadOS
- Classifications
- T1528
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 8, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <14.6
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
- WebKit CORS redirect URL disclosure demonstrationproof 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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