Quiz order bypass via unchecked web-service responses
Published Mar 24, 2023 · Updated Feb 20, 2025
Improper authorization in Moodle LMS allows remote authenticated users to bypass sequential navigation during a quiz attempt. The mod_quiz web-service response builder appends question data without calling quiz_attempt::check_page_access, so later pages are returned regardless of the attempt's current page. Exploitation requires student access to an in-progress quiz configured for sequential navigation and permits viewing questions ahead of the enforced order.
Summary
What happened
Improper authorization in Moodle LMS allows remote authenticated users to bypass sequential navigation during a quiz attempt. The mod_quiz web-service response builder appends question data without calling quiz_attempt::check_page_access, so later pages are returned regardless of the attempt's current page. Exploitation requires student access to an in-progress quiz configured for sequential navigation and permits viewing questions ahead of the enforced order.
The record
- CVE
- CVE-2022-40208
- Published
- Mar 24, 2023
- Updated
- Feb 20, 2025
- Vendor
- Moodle
- Product
- Moodle LMS
- Classifications
- CWE-285
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 24, 2023CVE publishedPublication date reported by the CVE source.
- Feb 20, 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=affected 4.0 to 4.0.2, 3.11 to 3.11.8, 3.9 to 3.9.15 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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