Blind SSRF via unchecked redirect destinations
Published Mar 6, 2023 · Updated Mar 5, 2025
SSRF in Moodle LMS 3.11, 3.10 through 3.10.4, and 3.9.7 and earlier allows remote attackers to send blind server requests. The cURL wrapper follows attacker-controlled redirects without reapplying blocked-host and allowed-port checks to each destination. Any network-reachable feature that passes an attacker-controlled URL into the wrapper exposes internal hosts or disallowed ports to blind requests.
Summary
What happened
SSRF in Moodle LMS 3.11, 3.10 through 3.10.4, and 3.9.7 and earlier allows remote attackers to send blind server requests. The cURL wrapper follows attacker-controlled redirects without reapplying blocked-host and allowed-port checks to each destination. Any network-reachable feature that passes an attacker-controlled URL into the wrapper exposes internal hosts or disallowed ports to blind requests.
The record
- CVE
- CVE-2021-36396
- Published
- Mar 6, 2023
- Updated
- Mar 5, 2025
- Vendor
- Moodle
- Product
- Moodle LMS
- Classifications
- CWE-918, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 6, 2023CVE publishedPublication date reported by the CVE source.
- Mar 5, 2025Record 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=3.11, 3.10 to 3.10.4, 3.9 to 3.9.7 and earlier unsupported versions
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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