CVE-1999-0959 in IRIX
Summary
by MITRE
irix startmidi program allows local users to modify arbitrary files via a symlink attack.
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Analysis
by VulDB Data Team • 09/03/2024
The vulnerability identified as CVE-1999-0959 resides within the irix startmidi program on IRIX operating systems, representing a classic symlink attack scenario that exploits insecure file handling practices. This issue affects local users who can leverage symbolic link manipulation to gain unauthorized access to modify files outside their intended scope. The flaw manifests when the startmidi program creates temporary files without proper validation of symbolic link conditions, allowing attackers to redirect file operations to sensitive system locations. The vulnerability operates at the file system level and demonstrates poor privilege separation between the program execution context and the file system operations it performs.
The technical implementation of this vulnerability stems from the program's failure to properly handle file creation in a predictable manner. When startmidi executes and attempts to create temporary files, it does not verify whether the target path contains symbolic links that could be manipulated by an attacker. This insecure practice creates a race condition where an attacker can establish a symbolic link at a specific location before the program attempts to create a file there, thereby redirecting the program's file operations to arbitrary locations in the filesystem. The attack vector specifically targets the program's temporary file creation mechanism and relies on the assumption that file paths are immutable during program execution, which is not validated in the vulnerable implementation.
The operational impact of this vulnerability extends beyond simple unauthorized file modification, as it can potentially allow local users to escalate privileges or compromise system integrity. An attacker could use this technique to modify critical system files, configuration data, or even executable programs that are processed by the startmidi application. The vulnerability is particularly concerning in multi-user environments where local access might be limited but the attacker can leverage the program's insecure behavior to gain broader system access. This represents a privilege escalation vector that can be exploited without requiring remote network access, making it particularly dangerous in environments where local users have limited but persistent access to the system.
Mitigation strategies for CVE-1999-0959 should focus on implementing proper file system validation mechanisms and eliminating the race condition inherent in the vulnerable program design. The recommended approach involves modifying the startmidi program to use atomic file creation methods that prevent symbolic link manipulation during file operations, such as creating files with unique names and verifying the actual file system object before proceeding with operations. Additionally, the program should validate all file paths for symbolic link conditions before attempting file creation, and implement proper privilege separation to limit the scope of file system operations. Organizations should also consider implementing file system monitoring and access control mechanisms to detect unauthorized file modifications. This vulnerability aligns with CWE-377 which addresses insecure temporary file handling and CWE-276 which covers improper file permissions, both of which are fundamental security principles that should be enforced in system programming practices. The attack pattern follows typical privilege escalation techniques documented in the ATT&CK framework under privilege escalation tactics, specifically focusing on local privilege escalation through insecure file handling mechanisms.