CVE-2014-1838 in openSUSE
Summary
by MITRE
The (1) extract_keys_from_pdf and (2) fill_pdf functions in pdf_ext.py in logilab-commons before 0.61.0 allows local users to overwrite arbitrary files and possibly have other unspecified impact via a symlink attack on /tmp/toto.fdf.
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Analysis
by VulDB Data Team • 05/07/2026
The vulnerability identified as CVE-2014-1838 represents a critical file system exposure in the logilab-commons library version 0.61.0 and earlier. This flaw manifests within the pdf_ext.py module where two specific functions extract_keys_from_pdf and fill_pdf are susceptible to exploitation through symbolic link attacks. The vulnerability stems from improper handling of temporary files during PDF processing operations, creating a path traversal scenario that enables attackers to manipulate the file system in unintended ways.
The technical implementation of this vulnerability occurs when the affected functions create temporary files in the /tmp directory without adequate security checks or atomic file creation mechanisms. The specific file path /tmp/toto.fdf becomes the target of the symbolic link attack where an attacker can establish a symlink pointing to a system file or directory. When the vulnerable functions execute, they process the symlinked file path as if it were the legitimate temporary file, resulting in arbitrary file overwrite capabilities. This represents a classic race condition vulnerability where the temporary file creation and usage phases are not properly synchronized or secured against malicious interference.
The operational impact of this vulnerability extends beyond simple file overwrites to potentially enable broader system compromise. An attacker with local access can leverage this weakness to modify critical system files, configuration data, or sensitive information stored in locations accessible to the running process. The unspecified additional impacts mentioned in the CVE description suggest potential for privilege escalation or denial of service conditions, as the attacker could potentially overwrite system binaries or critical configuration files. This vulnerability aligns with CWE-377: Insecure Temporary File and CWE-378: Creation of Temporary File With Insecure Permissions, both of which address the fundamental security issues surrounding temporary file handling in software applications.
From an attack perspective, this vulnerability follows patterns consistent with the MITRE ATT&CK framework's T1059.007 technique for Command and Scripting Interpreter: Python, as it exploits Python-based libraries to achieve unauthorized file system modifications. The attack requires local system access but can be particularly dangerous in multi-user environments where attackers might gain access through legitimate user accounts or by compromising services running with elevated privileges. The vulnerability's exploitation is straightforward and does not require specialized tools or complex attack chains, making it a significant risk for systems where logilab-commons is utilized for PDF processing operations.
The recommended mitigations for this vulnerability include immediate upgrading to logilab-commons version 0.61.0 or later, where the temporary file handling has been corrected to use secure file creation methods. Organizations should implement proper temporary file management practices including using secure temporary directories with appropriate permissions, implementing atomic file creation patterns, and avoiding predictable temporary file names. System administrators should also conduct comprehensive audits of applications using this library to ensure proper file system permissions and implement monitoring for unauthorized file system modifications. The fix addresses the underlying race condition by ensuring that temporary files are created with exclusive access permissions and are not susceptible to symbolic link attacks during the processing lifecycle.