Open redirect via protocol-relative Location header
Published May 24, 2021 · Updated Sep 17, 2024
Open redirect in Fardog trailing-slash before 2.0.1 allows remote attackers to redirect users to arbitrary sites via double-leading-slash URLs. The createTrailing function writes the formatted request URL directly to the Location header, so a path beginning with // becomes a protocol-relative external URL. Exploitation requires an application to expose the middleware and a user to follow the resulting redirect, enabling phishing or credential theft.
Summary
What happened
Open redirect in Fardog trailing-slash before 2.0.1 allows remote attackers to redirect users to arbitrary sites via double-leading-slash URLs. The createTrailing function writes the formatted request URL directly to the Location header, so a path beginning with // becomes a protocol-relative external URL. Exploitation requires an application to expose the middleware and a user to follow the resulting redirect, enabling phishing or credential theft.
The record
- CVE
- CVE-2021-23387
- Published
- May 24, 2021
- Updated
- Sep 17, 2024
- Vendor
- Fardog
- Product
- trailing-slash
- Classifications
- CWE-601, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 24, 2021CVE publishedPublication date reported by the CVE source.
- Sep 17, 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 <2.0.1
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
- Snyk double-slash redirect proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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