CVE-2012-2451 in Config-inifiles
Summary
by MITRE
The Config::IniFiles module before 2.71 for Perl creates temporary files with predictable names, which allows local users to overwrite arbitrary files via a symlink attack. NOTE: some of these details are obtained from third party information. NOTE: it has been reported that this might only be exploitable by writing in the same directory as the .ini file. If this is the case, then this issue might not cross privilege boundaries.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/05/2021
The Config::IniFiles Perl module vulnerability identified as CVE-2012-2451 represents a significant security flaw in how temporary files are handled during configuration file processing. This vulnerability affects versions prior to 2.71 and stems from the module's predictable temporary file naming mechanism that creates files with easily guessable names. The flaw enables local attackers to perform symlink attacks against the temporary file creation process, potentially allowing them to overwrite arbitrary files on the system. The vulnerability operates at the file system level and demonstrates poor security practices in temporary file management, which aligns with CWE-377 - Insecure Temporary File creation and CWE-378 - Creation of Temporary File With Insecure Permissions.
The technical implementation of this vulnerability occurs when the Config::IniFiles module processes configuration files and creates temporary files during parsing operations. When the module generates these temporary files, it uses predictable naming conventions that make it possible for an attacker to create symbolic links with the same names before the legitimate temporary file is created. This race condition allows the attacker to control what gets written to the target file, potentially leading to privilege escalation or arbitrary code execution depending on the context in which the module operates. The attack vector specifically targets the directory containing the .ini file, as noted in the vulnerability description, which limits the scope of exploitation but still presents a meaningful security risk.
The operational impact of this vulnerability extends beyond simple file overwrites, as it can be leveraged to compromise system integrity and potentially escalate privileges. When the vulnerable module is used in applications running with elevated privileges, such as system administration tools or web applications with write permissions, the consequences become more severe. Attackers can exploit this flaw to replace critical system files, configuration files, or even binaries with malicious content, potentially leading to persistent backdoors or complete system compromise. The vulnerability's classification under the ATT&CK framework would fall under privilege escalation techniques, specifically leveraging insecure temporary file creation to gain elevated system access. This represents a common attack pattern that has been documented in various security advisories and penetration testing reports.
Mitigation strategies for CVE-2012-2451 focus primarily on upgrading to version 2.71 or later of the Config::IniFiles module where the temporary file handling has been corrected. System administrators should also implement proper file system permissions and access controls to limit the impact of potential exploitation. Additional defensive measures include monitoring for unusual file creation patterns in directories containing configuration files, implementing proper file system auditing, and ensuring that applications using this module run with minimal required privileges. The vulnerability serves as a reminder of the importance of secure coding practices in temporary file handling and demonstrates how seemingly minor implementation flaws can create significant security risks when exploited in the right context. Organizations should conduct thorough vulnerability assessments to identify all systems using vulnerable versions of this Perl module and ensure proper patch management procedures are in place to prevent exploitation.