CVE-2012-4131 in NX-OS
Summary
by MITRE
Directory traversal vulnerability in tar in Cisco NX-OS allows local users to access arbitrary files via crafted command-line arguments, aka Bug IDs CSCty07157, CSCty07159, CSCty07162, and CSCty07164.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 06/04/2021
The vulnerability identified as CVE-2012-4131 represents a directory traversal flaw within the tar utility implementation in Cisco NX-OS operating system. This critical security weakness affects network devices running Cisco NX-OS software, particularly those utilizing the tar command for archive operations. The vulnerability stems from insufficient input validation and sanitization of command-line arguments passed to the tar utility, creating an avenue for malicious exploitation by local attackers who possess system access.
The technical exploitation of this vulnerability occurs through carefully crafted command-line arguments that manipulate the tar utility's behavior to traverse directory structures beyond intended boundaries. When tar processes these malicious arguments, it fails to properly validate the paths specified, allowing attackers to reference files outside the intended directory scope. This flaw specifically manifests in the handling of archive extraction operations where relative path references can be manipulated to access sensitive system files, configuration data, or other restricted resources. The vulnerability is categorized under CWE-22, which represents "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", a well-documented weakness in software security practices.
The operational impact of this directory traversal vulnerability extends beyond simple file access, as it provides attackers with the capability to read arbitrary files on the system. Local users who can execute tar commands can potentially access sensitive configuration files, system logs, or other confidential data that should remain restricted. This access could lead to information disclosure, privilege escalation, or the ability to gather intelligence for further attacks. The vulnerability affects multiple Cisco NX-OS versions and impacts network infrastructure devices that rely on tar for backup, restore, or archive operations, making it particularly concerning for enterprise environments where these devices serve critical network functions.
Security practitioners should implement immediate mitigations including applying the latest Cisco security patches and updates that address this specific vulnerability. System administrators should also review and restrict local user permissions where possible, ensuring that only authorized personnel have access to tar command functionality. Network segmentation and monitoring of file access patterns can help detect potential exploitation attempts. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other instances of similar path traversal flaws within their NX-OS environments. The ATT&CK framework categorizes this vulnerability under T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1005 for "Data from Local System", highlighting the attack vectors and potential data exfiltration capabilities that this vulnerability enables for threat actors.