CVE-2008-4908 in CrossFire
Summary
by MITRE
maps/Info/combine.pl in CrossFire crossfire-maps 1.11.0 allows local users to overwrite arbitrary files via a symlink attack on a temporary file.
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Analysis
by VulDB Data Team • 10/13/2018
The vulnerability identified as CVE-2008-4908 affects the CrossFire crossfire-maps 1.11.0 software package, specifically within the maps/Info/combine.pl script. This represents a classic race condition and insecure temporary file handling flaw that enables local attackers to perform privilege escalation through symbolic link manipulation. The issue stems from the script's failure to properly validate or secure temporary files during its execution lifecycle, creating a window of opportunity for malicious actors to exploit the system's file permissions and overwrite critical system files.
The technical implementation of this vulnerability involves the combine.pl script creating temporary files without proper security measures such as using secure temporary file creation functions or implementing proper file access controls. When local users can predict or influence the location of temporary files, they can establish symbolic links that point to sensitive system files, causing the script to write data to locations other than intended. This type of attack falls under the category of time-of-check to time-of-use race conditions, where the system checks for file existence or permissions at one point in time but the actual file operation occurs later when the attacker may have already manipulated the file system.
From an operational impact perspective, this vulnerability allows local users to potentially overwrite any file that the crossfire-maps process has write permissions to, which could include system configuration files, binary executables, or other critical system resources. The attack vector specifically targets local users rather than remote attackers, making it particularly dangerous in multi-user environments where privilege escalation could lead to system compromise. The vulnerability aligns with CWE-362 which describes concurrent execution use of a resource, and CWE-367 which covers time-of-check to time-of-use race conditions, both of which are fundamental security flaws in Unix-like systems. The ATT&CK framework categorizes this under privilege escalation techniques, specifically T1068 which involves exploiting vulnerabilities in legitimate programs.
Mitigation strategies for this vulnerability should focus on implementing proper temporary file handling practices such as using secure temporary file creation functions like mkstemp() or mkdtemp() that provide atomic creation of temporary files with restricted permissions. System administrators should ensure that the crossfire-maps package is updated to versions that address this specific vulnerability, and if the software cannot be updated, implementing proper file system permissions and access controls can help limit the impact. The system should also be configured to run with minimal necessary privileges, and monitoring should be implemented to detect unauthorized file modifications. Additionally, the principle of least privilege should be applied to ensure that the combine.pl script does not operate with unnecessary write permissions to sensitive system locations. This vulnerability highlights the importance of secure coding practices and proper file system security measures in preventing local privilege escalation attacks.