CVE-2015-2186 in edX
Summary
by MITRE
The Ansible edxapp role in the Configuration Repo in edX allows remote websites to spoof edX accounts by leveraging use of the string literal "False" instead of a boolean False for the CORS_ORIGIN_ALLOW_ALL setting. Note: this vulnerability was fixed on 2015-03-06, but the version number was not changed.
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Analysis
by VulDB Data Team • 02/03/2023
The vulnerability described in CVE-2015-2186 resides within the Ansible edxapp role configuration repository used by the edX learning platform. This issue represents a critical security flaw that emerged from a specific implementation choice in the CORS (Cross-Origin Resource Sharing) configuration settings. The vulnerability specifically affects the CORS_ORIGIN_ALLOW_ALL parameter which controls how the platform handles cross-origin requests from external domains. When configured improperly with the string literal "False" instead of the proper boolean value False, the system fails to properly restrict cross-origin access, creating a potential vector for malicious actors to exploit.
The technical root cause of this vulnerability stems from a type confusion error in the configuration parsing logic. The CORS_ORIGIN_ALLOW_ALL setting should accept a boolean value to determine whether all origins are permitted to access the edX platform resources. However, when administrators configured this setting using the string literal "False" rather than the boolean False, the system's conditional logic failed to properly evaluate the configuration. This type mismatch created a scenario where the platform would incorrectly interpret the configuration and effectively disable the CORS restrictions. According to CWE-691, this vulnerability aligns with insecure configuration practices that can lead to improper input validation and processing. The flaw essentially allows any remote website to spoof edX accounts by manipulating the cross-origin request handling mechanism.
The operational impact of this vulnerability is severe and directly affects the platform's authentication and authorization security model. Attackers could potentially exploit this weakness to perform cross-site request forgery attacks or manipulate user sessions across different domains. The spoofing capability means that malicious actors could craft requests that appear to originate from legitimate edX domains, potentially gaining unauthorized access to user accounts or sensitive platform data. This vulnerability undermines the fundamental security boundaries that should protect user authentication and session management within the edX ecosystem. From an ATT&CK framework perspective, this represents a technique that could be leveraged for privilege escalation and credential theft through web application vulnerabilities, specifically under the T1566 category of "Phishing for Information" and T1078 for "Valid Accounts."
The remediation for this vulnerability required administrators to update their Ansible configuration files to properly use the boolean value False instead of the string literal "False" for the CORS_ORIGIN_ALLOW_ALL setting. This fix aligns with industry best practices for secure configuration management and input validation. Organizations should implement configuration management policies that enforce proper data types for security-critical parameters and conduct regular audits of configuration files to prevent similar issues. The vulnerability's resolution demonstrates the importance of proper type handling in security-sensitive applications and the need for comprehensive testing of configuration parameters before deployment. Security teams should establish automated validation checks that can identify such type mismatches in configuration files to prevent exploitation before it occurs.