CVE-2015-2267 in Moodle
Summary
by MITRE
mdeploy.php in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4 allows remote authenticated users to bypass intended access restrictions and extract archives to arbitrary directories via a crafted dataroot value.
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Analysis
by VulDB Data Team • 04/15/2022
The vulnerability identified as CVE-2015-2267 affects Moodle versions through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4, specifically within the mdeploy.php component. This issue represents a critical access control flaw that enables remote authenticated attackers to circumvent intended security restrictions. The vulnerability stems from improper validation of the dataroot parameter, which is a critical configuration element in Moodle that defines the directory where user data and files are stored. When exploited, this weakness allows attackers to manipulate the extraction path of archived files, potentially leading to arbitrary file operations within the system's file structure.
The technical exploitation of this vulnerability involves crafting a malicious dataroot value that bypasses the intended access controls governing file extraction operations. This flaw falls under the CWE-22 category of "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')" and aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter. The vulnerability exists because the mdeploy.php script fails to properly sanitize or validate user-supplied dataroot values before using them in file system operations. Attackers can leverage this by authenticating to the system with legitimate credentials and then submitting a crafted dataroot parameter that points to arbitrary directories outside the intended scope, effectively allowing them to extract archive contents to locations they should not have access to.
The operational impact of this vulnerability extends beyond simple unauthorized file access, as it can enable attackers to potentially overwrite critical system files, inject malicious code into the application, or escalate their privileges within the Moodle environment. This weakness particularly affects organizations that rely on Moodle for educational content management and user data handling, as it could compromise the integrity of the entire learning management system. The vulnerability's exploitation requires only authenticated access, making it particularly dangerous in environments where user accounts might be compromised through other means such as credential theft or social engineering attacks.
Organizations should immediately apply the vendor-provided patches and updates for affected Moodle versions to remediate this vulnerability. The fix typically involves implementing proper input validation and sanitization of the dataroot parameter within the mdeploy.php script, ensuring that all user-supplied paths are properly checked against allowed directories. Additionally, system administrators should review and tighten access controls for Moodle installations, implement network segmentation, and monitor for suspicious file operations within the dataroot directories. Security teams should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability. The remediation process should include comprehensive testing to ensure that the patch does not introduce regressions in legitimate functionality while maintaining the security hardening measures.