User redirection via unsanitized return path
Published Sep 12, 2021 · Updated Sep 16, 2024
Open redirect in thoughtbot Clearance before 2.5.0 allows remote attackers to send users to an external site after sign-in. The return_to method parses session[:return_to] but preserves multiple leading slashes, which produce an external redirect target. Exploitation requires application logic that lets an attacker influence the session value and a user who completes the sign-in flow.
Summary
What happened
Open redirect in thoughtbot Clearance before 2.5.0 allows remote attackers to send users to an external site after sign-in. The return_to method parses session[:return_to] but preserves multiple leading slashes, which produce an external redirect target. Exploitation requires application logic that lets an attacker influence the session value and a user who completes the sign-in flow.
The record
- CVE
- CVE-2021-23435
- Published
- Sep 12, 2021
- Updated
- Sep 16, 2024
- Vendor
- thoughtbot
- Product
- Clearance
- Classifications
- CWE-601, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 12, 2021CVE publishedPublication date reported by the CVE source.
- Sep 16, 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 <2.5.0
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
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Technologies
Your stack
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Your stack
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