CVE-2014-5260 in XML-DT
Summary
by MITRE
The (1) mkxmltype and (2) mkdtskel scripts in XML-DT before 0.64 allow local users to overwrite arbitrary files via a symlink attack on a /tmp/_xml_##### temporary file.
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Analysis
by VulDB Data Team • 03/28/2022
The vulnerability identified as CVE-2014-5260 affects XML-DT versions prior to 0.64 and involves two critical scripts named mkxmltype and mkdtskel. These scripts create temporary files in the /tmp directory with predictable naming patterns using the prefix xml followed by random characters. The flaw stems from the insecure handling of temporary file creation, where the scripts do not properly validate or secure the temporary file paths before writing to them. This vulnerability falls under the category of insecure temporary file handling as defined by CWE-377, specifically representing a race condition scenario where an attacker can exploit the time gap between file creation and file usage to perform malicious file overwrites.
The technical implementation of this vulnerability exploits a classic symlink attack pattern that allows local users to manipulate the system's temporary file creation process. When the mkxmltype and mkdtskel scripts execute, they generate temporary files in /tmp directory without proper security measures such as using secure temporary file creation functions or validating file ownership. An attacker can create symbolic links in the /tmp directory that point to sensitive system files or configuration files, and when the vulnerable scripts attempt to write to the temporary file, they inadvertently overwrite the target files that the symbolic links point to. This creates a privilege escalation scenario where local users can potentially modify system-critical files that they would normally not have write access to.
The operational impact of this vulnerability is significant as it enables local privilege escalation attacks that can compromise system integrity and potentially lead to broader security breaches. Attackers can leverage this vulnerability to overwrite critical system files such as configuration files, binaries, or even system libraries, which could result in system instability, unauthorized access, or complete system compromise. The vulnerability is particularly dangerous because it requires minimal privileges to exploit and can be used to gain elevated access to the system. From an attack framework perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1059 (Command and Scripting Interpreter) and T1068 (Local Privilege Escalation) tactics, as it provides a method for local users to escalate their privileges through file system manipulation.
The mitigation strategies for this vulnerability involve immediate patching of XML-DT to version 0.64 or later, which addresses the insecure temporary file handling by implementing proper file creation security measures. System administrators should also implement additional security controls such as setting proper permissions on the /tmp directory, using secure temporary file creation functions like mkstemp(), and monitoring for suspicious symlink creation patterns. Organizations should conduct regular vulnerability assessments to identify similar insecure temporary file handling patterns in other applications and systems. The fix typically involves modifying the scripts to use atomic temporary file creation methods that prevent symlink attacks by ensuring that the file is created with exclusive access rights or by using secure temporary directory mechanisms that are resistant to such attacks. Additionally, implementing proper file system permissions and monitoring for unauthorized file system modifications can help detect and prevent exploitation attempts of this class of vulnerability.