CVE-2002-2267 in Bogopass Email Filter
Summary
by MITRE
bogopass in bogofilter 0.9.0.4 allows local users to overwrite arbitrary files via a symlink attack on the bogopass temporary file.
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Analysis
by VulDB Data Team • 04/20/2019
The vulnerability identified as CVE-2002-2267 resides within the bogofilter email spam filtering tool version 0.9.0.4, specifically affecting the bogopass utility component. This issue represents a classic temporary file creation vulnerability that enables local attackers to manipulate file system permissions and overwrite arbitrary files through symbolic link manipulation. The flaw occurs during the temporary file handling process where the application creates temporary files without proper security checks, making it susceptible to race conditions and symlink attacks that can be exploited by malicious users with local access to the system.
The technical implementation of this vulnerability stems from improper temporary file handling practices within the bogopass utility. When the application generates temporary files, it does not adequately verify the existence or ownership of these files before writing to them, creating a window of opportunity for attackers to establish symbolic links with the same names as the temporary files. This weakness aligns with CWE-377, which addresses insecure temporary file creation practices, and specifically demonstrates the dangers of predictable temporary file names and insufficient file access controls. The vulnerability operates under the principle of time-of-check to time-of-use flaws where the system checks for file existence and permissions at one point but the actual file operations occur later, allowing for manipulation between these checks.
From an operational perspective, this vulnerability poses significant risks to systems running bogofilter, particularly in multi-user environments where local privilege escalation could occur. An attacker with local access can exploit this flaw to overwrite critical system files, configuration files, or even files belonging to other users. The impact extends beyond simple file overwrites as it could potentially allow for privilege escalation, data corruption, or information disclosure depending on the target files. The vulnerability is particularly concerning in environments where bogofilter is used for automated email filtering, as it could be leveraged to disrupt email services or gain unauthorized access to sensitive information. This weakness also aligns with ATT&CK technique T1059.007 for execution through command and scripting interpreter, as attackers might use this vulnerability to establish persistence or escalate privileges.
Mitigation strategies for CVE-2002-2267 involve several approaches that address the root causes of the vulnerability. System administrators should immediately upgrade to a patched version of bogofilter that implements secure temporary file creation practices, ensuring that temporary files are created with appropriate permissions and are not predictable in their naming or location. The implementation should include checks for existing symbolic links and proper file ownership verification before any write operations occur. Additionally, the system should employ secure temporary file creation methods such as using mkstemp() or similar functions that create files with exclusive access permissions. Organizations should also consider implementing file system monitoring and access controls to detect and prevent unauthorized file modifications. The vulnerability demonstrates the importance of following secure coding practices as outlined in the OWASP Secure Coding Guidelines, particularly regarding temporary file handling and privilege management. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other applications, as this type of flaw often indicates broader security weaknesses in software development practices that require comprehensive remediation rather than isolated fixes.