CVE-2012-3504 in crypto-utils
Summary
by MITRE
The nssconfigFound function in genkey.pl in crypto-utils 2.4.1-34 allows local users to overwrite arbitrary files via a symlink attack on the "list" file in the current working directory.
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Analysis
by VulDB Data Team • 12/19/2021
The vulnerability identified as CVE-2012-3504 resides within the nssconfigFound function of genkey.pl script in the crypto-utils package version 2.4.1-34. This flaw represents a classic symlink attack scenario that exploits insecure temporary file handling practices. The vulnerability manifests when the script creates or processes a "list" file in the current working directory without proper validation of the file's existence or ownership. Local attackers can leverage this weakness by creating a symbolic link with the name "list" that points to a target file they wish to overwrite, thereby enabling arbitrary file modification through the script's execution.
The technical implementation of this vulnerability aligns with CWE-376, which addresses improper neutralization of special elements used in file names or paths. The flaw occurs because the genkey.pl script does not perform proper file validation before operating on the "list" file. When the nssconfigFound function executes, it assumes the file exists and proceeds with operations that ultimately result in overwriting the target file that the malicious symlink points to. This behavior constitutes a race condition vulnerability where the timing of file creation and access creates an exploitable window for privilege escalation or data corruption.
From an operational perspective, this vulnerability presents significant risks for systems running the affected crypto-utils package. The local user exploitation capability means that any user with access to execute the genkey.pl script can potentially overwrite critical system files or configuration data. The impact extends beyond simple file corruption as attackers could target sensitive files such as system configuration, user credentials, or even binary executables that might be overwritten with malicious content. The attack vector is particularly concerning because it requires minimal privileges and can be executed without network access, making it a persistent threat within compromised systems.
The vulnerability demonstrates clear alignment with ATT&CK technique T1059.007 for execution through scripting and T1068 for local privilege escalation. Organizations should implement immediate mitigations including upgrading to patched versions of crypto-utils, implementing proper file validation in the script, and ensuring that temporary file operations use secure patterns such as creating files with unique names and proper permissions. System administrators should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to critical system files. Additionally, the principle of least privilege should be enforced to limit which users can execute the vulnerable script, while regular security audits should verify that no symbolic links exist in directories where such scripts operate. The vulnerability serves as a reminder of the critical importance of secure temporary file handling practices in system administration scripts and the potential for seemingly benign file operations to become significant security risks when proper validation is omitted.