CVE-2019-10133 in Moodle
Summary
by MITRE
A flaw was found in Moodle before 3.7, 3.6.4, 3.5.6, 3.4.9 and 3.1.18. The form to upload cohorts contained a redirect field, which was not restricted to internal URLs.
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Analysis
by VulDB Data Team • 09/08/2025
This vulnerability exists in Moodle learning management systems prior to specific version releases including 3.7, 3.6.4, 3.5.6, 3.4.9, and 3.1.18. The flaw resides within the cohort upload functionality where a redirect field is improperly validated. This represents a classic insecure direct object reference vulnerability that allows attackers to manipulate the redirect behavior during cohort creation processes. The vulnerability falls under CWE-601 which specifically addresses URL redirect validation issues and can be categorized under the broader ATT&CK technique T1190 for exploiting vulnerabilities in web applications. The redirect field in the cohort upload form accepts external URLs without proper validation, creating potential pathways for malicious redirection attacks.
The technical implementation of this flaw allows an attacker to specify any URL in the redirect parameter when uploading cohort data through the Moodle interface. When the system processes the upload form, it fails to validate that the redirect URL belongs to the same domain or is otherwise trusted. This validation gap enables attackers to craft malicious requests that could redirect users to phishing sites, malicious domains, or exploit other attack vectors. The vulnerability is particularly concerning because cohort management is a core administrative function that typically requires elevated privileges, making successful exploitation potentially more impactful. Attackers could leverage this to redirect administrators to malicious sites during routine cohort management tasks, potentially harvesting credentials or executing further attacks.
The operational impact of this vulnerability extends beyond simple redirection attacks as it can facilitate more sophisticated social engineering campaigns. Administrators performing routine cohort uploads may unknowingly be redirected to attacker-controlled sites, especially if the redirect occurs after successful form submission. This creates opportunities for credential harvesting, malware distribution, or information theft. The vulnerability affects multiple Moodle versions, indicating it was likely present for an extended period and could have been exploited by threat actors who identified the pattern. Organizations using older Moodle versions without proper patch management are particularly at risk, as the vulnerability provides a clear attack vector that requires minimal technical expertise to exploit.
Mitigation strategies for this vulnerability include immediate patching to the affected Moodle versions as specified in the security advisories. Organizations should ensure their Moodle installations are updated to at least version 3.7, 3.6.4, 3.5.6, 3.4.9, or 3.1.18 respectively. Additionally, administrators should implement proper input validation at the application level to restrict redirect URLs to internal domains only. Network-level controls such as web application firewalls can provide additional protection by filtering suspicious redirect parameters. Regular security audits should include validation of form parameters and redirect handling to prevent similar issues. The vulnerability demonstrates the importance of proper access control and input validation in web applications, particularly those handling administrative functions. Organizations should also implement security awareness training for administrators to recognize potential redirect-based attacks and establish robust patch management processes to prevent exploitation of known vulnerabilities.