CVE-2012-0808 in as31
Summary
by MITRE
as31 2.3.1-4 does not seed the random number generator and generates predictable temporary file names, which makes it easier for local users to create or truncate files via a symlink attack.
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Analysis
by VulDB Data Team • 02/16/2019
The vulnerability identified as CVE-2012-0808 affects the as31 package version 2.3.1-4 and represents a critical weakness in the generation of temporary file names and random number seeding. This flaw stems from the application's failure to properly initialize its random number generator, creating predictable sequences that adversaries can exploit to manipulate file operations. The issue specifically impacts local users who can leverage this predictability to perform symlink attacks against the system.
The technical implementation of this vulnerability demonstrates poor cryptographic practices and inadequate entropy sources within the application's temporary file creation mechanism. When as31 generates temporary file names, it relies on a seeded random number generator that has not been properly initialized with sufficient entropy. This results in deterministic patterns that can be reverse-engineered by attackers, particularly those with local system access. The predictable nature of these temporary file names creates opportunities for attackers to manipulate the file system through symlink attacks where they can create symbolic links pointing to sensitive files or directories.
From an operational perspective, this vulnerability enables local privilege escalation and file manipulation attacks that can have significant security implications. Attackers can exploit the predictable temporary file names to create symbolic links that will be followed by the vulnerable application, potentially allowing them to overwrite or truncate critical system files, modify configuration data, or gain unauthorized access to restricted resources. The impact extends beyond simple file manipulation as it can be leveraged to bypass access controls and potentially escalate privileges within the system. This type of vulnerability aligns with CWE-330, which addresses the use of insufficiently random values, and represents a classic example of weak random number generation in security-sensitive applications.
The attack vector for this vulnerability is particularly concerning as it requires only local system access and leverages predictable temporary file naming patterns. Attackers can monitor the application's behavior to identify temporary file creation patterns and then establish symbolic links that will be resolved by the vulnerable application. This approach is consistent with ATT&CK technique T1059.001 for executing commands through local system access and T1068 for local privilege escalation. The vulnerability can be exploited across multiple scenarios including when the application runs with elevated privileges, making the potential impact even more severe. Organizations should consider implementing proper entropy sources and ensuring that all random number generators used in security-sensitive applications are properly seeded with sufficient randomness.
Mitigation strategies for CVE-2012-0808 should focus on addressing the root cause of the weak random number generation within the as31 package. System administrators should immediately update to a patched version of the package that properly initializes random number generators and implements secure temporary file creation mechanisms. The fix should ensure that temporary file names are generated using cryptographically secure random number generators with sufficient entropy. Additionally, implementing proper file system permissions and access controls can help reduce the impact of such vulnerabilities, though this does not address the core issue. Organizations should also consider implementing monitoring for suspicious file creation patterns and symbolic link manipulation that could indicate exploitation attempts. The vulnerability highlights the importance of following secure coding practices and adhering to industry standards such as those outlined in the OWASP Secure Coding Practices and NIST guidelines for random number generation in security applications.