CVE-2014-5509 in Perl
Summary
by MITRE
clipedit in the Clipboard module for Perl allows local users to delete arbitrary files via a symlink attack on /tmp/clipedit$$.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/20/2019
The vulnerability identified as CVE-2014-5509 resides within the Clipboard module for Perl, specifically in the clipedit utility that handles clipboard operations. This flaw represents a classic race condition and privilege escalation issue that affects local users with minimal privileges. The vulnerability stems from improper handling of temporary files during the clipboard editing process, creating a predictable temporary file path that can be exploited through symbolic link manipulation.
The technical implementation of this vulnerability exploits the insecure use of temporary file creation in the clipedit utility. When the utility executes, it creates a temporary file at /tmp/clipedit$$ where $$ represents the process ID, making the filename predictable to local attackers. The flaw occurs because the application does not properly validate or secure the temporary file creation process, allowing malicious users to establish symbolic links with the same name before the legitimate process creates the file. This creates a race condition where the attacker's symlink gets processed instead of the intended temporary file, enabling arbitrary file deletion operations.
This vulnerability operates under the attack pattern known as privilege escalation through insecure temporary file handling, which aligns with CWE-377 and CWE-378 categories. The operational impact is significant as it allows local users to delete files with the privileges of the user running the clipedit utility, which typically runs with elevated permissions. Attackers can leverage this weakness to remove critical system files, configuration data, or user documents, potentially causing system instability or complete data loss. The attack vector is particularly dangerous because it requires minimal privileges and can be executed repeatedly without requiring special tools or extensive system access.
The mitigation strategies for CVE-2014-5509 involve multiple layers of defense including immediate patching of affected Perl Clipboard modules, implementing proper temporary file handling mechanisms that use secure randomization or atomic file creation techniques, and ensuring that temporary files are created with appropriate permissions that prevent symlink attacks. Organizations should also implement proper privilege separation and consider using secure temporary file creation functions that are resistant to race conditions. From an ATT&CK framework perspective, this vulnerability maps to T1068 (Local Privilege Escalation) and T1548.001 (Abuse Elevation Control Mechanism), demonstrating how insecure temporary file handling can be exploited for privilege escalation purposes. The vulnerability highlights the critical importance of secure coding practices and proper file system permission management in preventing local privilege escalation attacks.