CVE-2014-1640 in axiom
Summary
by MITRE
axiom-test.sh in axiom 20100701-1.1 uses tempfile to create a safe temporary file but appends a suffix to the original filename and writes to this new filename, which allows local users to overwrite arbitrary files via a symlink attack on the new filename.
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Analysis
by VulDB Data Team • 03/06/2019
The vulnerability identified as CVE-2014-1640 resides in the axiom-test.sh script component of the axiom software suite version 20100701-1.1. This flaw represents a classic race condition vulnerability that exploits the improper handling of temporary files during script execution. The issue manifests when the script employs tempfile functionality to generate secure temporary files but subsequently appends a suffix to the original filename before writing to the new filename. This seemingly innocuous approach creates a dangerous scenario where local attackers can manipulate the file system through symbolic link attacks.
The technical implementation of this vulnerability stems from the insecure use of temporary file creation mechanisms within the shell script environment. When axiom-test.sh generates temporary files, it follows a pattern that creates a new filename by appending a suffix to the original, but this new filename becomes vulnerable to symlink-based attacks. The flaw lies in the timing window between when the temporary file is created and when it is written to, allowing malicious users to establish symbolic links that point to arbitrary target files. This creates a privilege escalation vector where local users can overwrite files with elevated privileges, potentially compromising system integrity.
The operational impact of CVE-2014-1640 extends beyond simple file overwrites as it enables attackers to manipulate critical system files or configuration data. The vulnerability operates at the local user level but can potentially be leveraged to gain unauthorized access to sensitive data or system resources. Attackers can exploit this weakness to modify system binaries, configuration files, or log data, thereby compromising the integrity of the affected system. The attack requires local access but can be particularly damaging when the script runs with elevated privileges, creating a pathway for privilege escalation attacks.
This vulnerability maps directly to CWE-377, which addresses insecure temporary file handling, and aligns with ATT&CK technique T1059.007 for executing malicious code through shell scripts. The attack vector follows the pattern of privilege escalation through file system manipulation, commonly observed in Unix-like environments where temporary file handling is not properly secured. Security practitioners should consider this vulnerability when implementing defense-in-depth strategies, particularly focusing on secure file handling practices and proper privilege management. The remediation approach involves ensuring that temporary files are created with proper permissions and that symbolic link checks are performed before file operations, preventing attackers from exploiting the race condition window. Organizations should also implement regular vulnerability assessments to identify similar insecure temporary file handling patterns across their software inventory, as this represents a common security flaw in shell script implementations.