Open redirect via backslash-tolerant URL sanitization
Published Sep 11, 2023 · Updated Sep 26, 2024
Open redirect in CouchCMS 2.3 allows remote attackers to send authenticated users to arbitrary sites through a crafted login URL. The sanitize_url() function in /couch/functions.php permits backslashes and fails to recognize an HTTPS value containing backslashes as an external URL; the browser then normalizes it and follows the resulting Location header. Exploitation requires the victim to submit a successful login request carrying the attacker-controlled redirect value, enabling redirection to an untrusted site.
Summary
What happened
Open redirect in CouchCMS 2.3 allows remote attackers to send authenticated users to arbitrary sites through a crafted login URL. The sanitize_url() function in /couch/functions.php permits backslashes and fails to recognize an HTTPS value containing backslashes as an external URL; the browser then normalizes it and follows the resulting Location header. Exploitation requires the victim to submit a successful login request carrying the attacker-controlled redirect value, enabling redirection to an untrusted site.
The record
- CVE
- CVE-2023-41609
- Published
- Sep 11, 2023
- Updated
- Sep 26, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-601, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 11, 2023CVE publishedPublication date reported by the CVE source.
- Sep 26, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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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
- CouchCMS 2.3 open redirect proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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