CVE-2008-4940 in aptoncd
Summary
by MITRE
xmlfile.py in aptoncd 0.1 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/aptoncd temporary file.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/13/2018
The vulnerability identified as CVE-2008-4940 resides within the xmlfile.py component of aptoncd version 0.1, a tool designed for managing cdrom installations. This flaw represents a classic symlink attack scenario that exploits insecure temporary file handling practices. The vulnerability specifically affects local users who can manipulate the system to overwrite arbitrary files through a carefully crafted symbolic link attack against the /tmp/aptoncd temporary file location.
The technical implementation of this vulnerability stems from improper handling of temporary files in the aptoncd application. When the application creates temporary files in the /tmp directory without adequate security measures, it becomes susceptible to race conditions where malicious users can establish symbolic links with the same names as expected temporary files. This allows attackers to redirect file operations to locations of their choosing, potentially overwriting critical system files or configuration data. The flaw directly relates to CWE-377, which addresses insecure temporary file creation practices, and CWE-378, which covers the creation of temporary files with insecure permissions.
The operational impact of this vulnerability extends beyond simple file overwrites, as it provides attackers with a means to escalate privileges and compromise system integrity. Local attackers can leverage this weakness to modify system-critical files, inject malicious code, or disrupt normal system operations. The attack vector specifically targets the /tmp directory which is commonly used for temporary file storage and typically lacks strict security controls. This vulnerability aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, and T1078, which addresses valid accounts usage, as attackers can exploit local access to manipulate the application's behavior.
Mitigation strategies for this vulnerability involve implementing proper temporary file handling practices including the use of secure temporary file creation functions that prevent symbolic link attacks. The application should employ techniques such as creating temporary files with unique names, setting appropriate file permissions, and using secure temporary directories. Additionally, the system should implement proper file access controls and monitoring to detect unauthorized file modifications. Organizations should ensure that all applications properly validate temporary file creation and avoid predictable naming schemes that could be exploited by attackers. The fix requires modifying the xmlfile.py script to implement secure temporary file handling mechanisms and eliminate the race condition that enables the symlink attack.