CVE-2004-0770 in DGen Emulator
Summary
by MITRE
romload.c in DGen Emulator 1.23 and earlier allows local users to overwrite arbitrary files via a symlink attack on temporary files during decompression of (1) gzip or (2) bzip ROM files.
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Analysis
by VulDB Data Team • 07/19/2017
The vulnerability identified as CVE-2004-0770 represents a critical security flaw in the DGen Emulator version 1.23 and earlier, specifically within the romload.c component responsible for handling ROM file decompression operations. This issue manifests as a race condition vulnerability that exploits the insecure handling of temporary files during the decompression process of both gzip and bzip compressed ROM files. The flaw occurs when the emulator creates temporary files without proper security measures, making it susceptible to symbolic link attacks that can be exploited by local users with minimal privileges.
The technical implementation of this vulnerability stems from the emulator's failure to properly validate or secure temporary file creation processes during decompression operations. When processing compressed ROM files, the system generates temporary files in predictable locations without implementing proper access controls or file validation mechanisms. Attackers can exploit this by creating symbolic links in the expected temporary file locations before the decompression process begins, effectively redirecting the write operations to arbitrary target files on the system. This type of attack falls under the category of time-of-check to time-of-use race conditions, where the system's security check occurs at a different point in time than the actual operation execution, creating a window of opportunity for exploitation.
The operational impact of this vulnerability extends beyond simple file overwriting, as it enables local privilege escalation and potential system compromise through carefully crafted symbolic link attacks. An attacker with access to the system can leverage this vulnerability to overwrite critical system files, configuration files, or even executables, potentially leading to unauthorized privilege escalation or persistent access. The vulnerability affects any user who has the ability to execute the DGen Emulator with sufficient privileges to create symbolic links, which in most system configurations represents a significant attack surface. This flaw particularly impacts gaming environments where emulator software is commonly used, as these systems often run with elevated privileges to access hardware resources.
Mitigation strategies for this vulnerability require immediate patching of the DGen Emulator to version 1.24 or later, where the developers have implemented proper temporary file handling mechanisms. The fix should ensure that temporary files are created with unique names and proper permissions, eliminating the race condition window that enables symbolic link attacks. Security best practices recommend implementing secure temporary file creation using functions that guarantee atomic creation and proper file ownership validation. Organizations should also consider implementing file system permissions that restrict symbolic link creation capabilities and employ monitoring solutions to detect suspicious file system activities. This vulnerability aligns with CWE-367, which addresses time-of-check to time-of-use race conditions, and maps to ATT&CK technique T1059 for execution through emulator environments, highlighting the need for comprehensive security controls in software development and deployment practices.