CVE-2012-5501 in Plone
Summary
by MITRE
at_download.py in Plone before 4.2.3 and 4.3 before beta 1 allows remote attackers to read arbitrary BLOBs (Files and Images) stored on custom content types via a crafted URL.
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Analysis
by VulDB Data Team • 03/13/2019
The vulnerability identified as CVE-2012-5501 affects the Plone content management system and represents a critical access control flaw that enables remote attackers to bypass authorization mechanisms. This issue specifically targets the at_download.py script within Plone versions prior to 4.2.3 and 4.3 beta 1, where improper validation of user input allows unauthorized access to sensitive binary objects stored within custom content types. The flaw exists in the handling of file download requests and demonstrates a classic path traversal or access control bypass vulnerability that can be exploited without authentication.
The technical implementation of this vulnerability stems from insufficient validation of the URL parameters used to retrieve BLOB data from the system's content repository. When a user requests access to a file through the at_download.py script, the application fails to properly verify whether the requesting user has appropriate permissions to access the specific BLOB resource. This weakness allows attackers to craft malicious URLs that reference arbitrary file paths within the Plone system's storage structure, effectively enabling them to retrieve any file that has been stored as a BLOB regardless of its intended access restrictions. The vulnerability specifically impacts custom content types that utilize BLOB storage for file and image handling, making it particularly dangerous in environments where sensitive documents are stored within these custom content structures.
The operational impact of CVE-2012-5501 extends beyond simple data exposure, as it can lead to significant information disclosure and potential system compromise. Attackers can leverage this vulnerability to access confidential documents, images, and other binary content that may contain sensitive information, intellectual property, or personally identifiable data. The implications are particularly severe in enterprise environments where Plone serves as a primary content management platform for organizational data. The vulnerability's remote exploitability means that attackers can target affected systems from outside the network perimeter, potentially leading to data breaches that could affect regulatory compliance, business operations, and organizational security posture. This flaw directly violates the principle of least privilege and demonstrates inadequate input validation practices that are commonly associated with CWE-20 input validation errors.
Organizations affected by this vulnerability should immediately implement the mitigation strategies recommended by the Plone security team, which primarily involve upgrading to supported versions of the software that contain proper access controls and input validation. The fix addresses the root cause by implementing proper authorization checks before allowing access to BLOB data, ensuring that only users with appropriate permissions can retrieve specific content objects. Security teams should also consider implementing network-level controls and monitoring for suspicious URL patterns that may indicate exploitation attempts. This vulnerability aligns with ATT&CK technique T1213.002 for Data from Information Repositories and demonstrates the importance of maintaining up-to-date software versions to prevent exploitation of known vulnerabilities. The incident underscores the critical need for regular security assessments and patch management processes to protect against similar access control flaws that could compromise sensitive data stored within content management systems.