CVE-2002-0271 in GNAT Pro Native
Summary
by MITRE
Runtime library in GNU Ada compiler (GNAT) 3.12p through 3.14p allows local users to modify files of other users via a symlink attack on temporary files.
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Analysis
by VulDB Data Team • 04/12/2019
The vulnerability identified as CVE-2002-0271 affects the GNU Ada compiler runtime library known as GNAT version 3.12p through 3.14p, representing a significant security flaw that enables local users to perform unauthorized file modifications through a carefully crafted symlink attack on temporary files. This issue stems from improper handling of temporary file creation within the compiler's runtime environment, creating a privilege escalation vector that can be exploited by malicious users to gain unauthorized access to other users' files. The vulnerability specifically targets the compiler's temporary file management mechanism, where the system creates temporary files without proper security checks that could be manipulated by attackers through symbolic link manipulation techniques.
The technical implementation of this flaw involves the compiler's runtime library creating temporary files in predictable locations without adequate permission checks or atomic file creation mechanisms. When the GNAT compiler processes Ada source code, it generates temporary files that are typically created with default permissions and in standard temporary directories. Attackers can exploit this by creating symbolic links with the same names as the temporary files that the compiler will create, effectively redirecting the compiler's file operations to target files owned by other users. This type of attack falls under the category of temporary file race conditions and symlink attacks, which are classified under CWE-377 as insecure temporary file creation and CWE-378 as creation of temporary files with insecure permissions.
The operational impact of this vulnerability extends beyond simple file modification capabilities, as it can enable attackers to escalate privileges and potentially compromise entire system security. Local users who can execute the compiler or any process that invokes it can leverage this flaw to modify files that they would normally not have access to, potentially including system configuration files, user data, or other sensitive resources. This vulnerability particularly affects multi-user systems where different users share the same system resources, making it a significant concern for development environments, shared computing platforms, and enterprise systems where the GNAT compiler is actively used. The attack vector is relatively simple to execute, requiring only the ability to create symbolic links in the target system's temporary directories, which are typically accessible to regular users.
Mitigation strategies for CVE-2002-0271 should focus on both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities in the compiler's runtime behavior. The most effective immediate solution involves upgrading to GNAT versions beyond 3.14p where this vulnerability has been addressed through proper temporary file creation mechanisms that include atomic operations and appropriate permission settings. System administrators should also implement temporary file security measures such as using secure temporary directory locations with restricted permissions, implementing proper file creation atomicity checks, and ensuring that all temporary file operations use secure methods that prevent symlink attacks. Additionally, organizations should consider implementing privilege separation techniques and restricting access to the compiler in environments where multiple users share the same system resources, aligning with the principle of least privilege as recommended in various security frameworks including those referenced in the MITRE ATT&CK framework for process injection and privilege escalation techniques. The vulnerability demonstrates the importance of secure coding practices in system libraries and the critical need for proper temporary file handling mechanisms that prevent attackers from manipulating file operations through symbolic link manipulation.