CVE-2004-2605 in Astats
Summary
by MITRE
aStats 1.6.5 allows local users to overwrite arbitrary files via a symlink attack on (1) the aStats-Graphic-Signature-Generation file and (2) certain PNG image files.
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Analysis
by VulDB Data Team • 06/30/2018
The vulnerability identified as CVE-2004-2605 affects aStats version 1.6.5, a web statistics application that generates graphical signatures and processes PNG image files. This issue represents a classic symlink attack vulnerability that exploits insecure temporary file creation practices within the application's file handling mechanisms. The flaw occurs when the application creates temporary files without proper security checks, allowing local attackers to manipulate the file system through symbolic link manipulation.
The technical implementation of this vulnerability stems from the application's failure to validate file paths and create temporary files securely. When aStats processes graphic signature generation and handles PNG image files, it creates temporary files in predictable locations without proper atomic file creation mechanisms. Attackers can exploit this by creating symbolic links with the same names as the temporary files that aStats intends to create, thereby redirecting the application's file operations to arbitrary locations on the file system. This allows attackers to overwrite existing files with malicious content or gain unauthorized access to sensitive system resources.
The operational impact of this vulnerability extends beyond simple file overwrites, as it can enable attackers to escalate privileges and compromise the entire system. Local users with minimal privileges can leverage this weakness to modify critical system files, potentially leading to privilege escalation or persistent backdoor installation. The vulnerability affects both the graphic signature generation process and PNG image handling components, making it particularly dangerous as it targets fundamental file processing functions. Attackers can use this weakness to overwrite configuration files, system binaries, or log files, creating opportunities for further exploitation.
Security practitioners should recognize this vulnerability as a manifestation of CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) flaws in file operations. The attack pattern aligns with ATT&CK technique T1059.007 for executing malicious code through file system manipulation and T1078 for gaining access to systems through local accounts. Mitigation strategies include implementing proper file path validation, using secure temporary file creation functions, and ensuring that all temporary file operations occur in secure directories with appropriate permissions. System administrators should also consider implementing file integrity monitoring solutions to detect unauthorized file modifications and apply the latest security patches for aStats to prevent exploitation. The vulnerability highlights the critical importance of secure coding practices in preventing symlink attacks and demonstrates how seemingly minor file handling issues can lead to significant security breaches.