CVE-2002-0399 in tar
Summary
by MITRE
Directory traversal vulnerability in GNU tar 1.13.19 through 1.13.25, and possibly later versions, allows attackers to overwrite arbitrary files during archive extraction via a (1) "/.." or (2) "./.." string, which removes the leading slash but leaves the "..", a variant of CVE-2001-1267.
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Analysis
by VulDB Data Team • 06/13/2019
The vulnerability identified as CVE-2002-0399 represents a critical directory traversal flaw within GNU tar versions ranging from 1.13.19 through 1.13.25 and potentially affecting subsequent releases. This security weakness stems from insufficient validation of file paths during archive extraction processes, creating a pathway for malicious actors to manipulate file system operations. The vulnerability specifically exploits the handling of path traversal sequences that begin with slash characters followed by directory navigation components, making it a variant of the previously documented CVE-2001-1267 that affected similar systems. The flaw manifests when tar encounters archive entries containing sequences such as "/.." or "./.." which should normally be interpreted as attempts to navigate up directory structures but are instead processed in a manner that allows arbitrary file overwrites.
The technical implementation of this vulnerability relies on the improper sanitization of file paths within the tar extraction routine. When GNU tar processes archive entries containing these specific traversal sequences, the software fails to properly canonicalize or validate the resulting file paths before performing write operations. This processing error occurs because the system removes the leading slash character from the path components while preserving the ".." elements, effectively allowing attackers to specify absolute paths that bypass normal directory boundaries. The vulnerability operates at the file system level where archive contents are extracted, making it particularly dangerous as it can target any location on the system where the extraction process has write permissions. This weakness falls under the Common Weakness Enumeration category CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal or Directory Traversal.
The operational impact of CVE-2002-0399 extends beyond simple file overwrites to encompass potential system compromise and data integrity violations. Attackers can leverage this vulnerability to overwrite critical system files, configuration files, or user data, potentially leading to privilege escalation or denial of service conditions. The vulnerability is particularly concerning in environments where tar is used to extract untrusted archives, such as in automated build systems, package management processes, or web application file uploads. The attack vector typically involves crafting malicious tar archives containing specially formatted file paths that, when extracted, cause the tar utility to write to locations outside the intended extraction directory. This flaw can be exploited in various scenarios including compromised web applications that accept file uploads, automated deployment systems, or any process that extracts tar archives without proper input validation, making it a significant concern for system administrators managing multiple services that rely on archive extraction functionality.
Mitigation strategies for CVE-2002-0399 focus on both immediate patching and operational security measures. The most effective solution involves upgrading to GNU tar versions that contain the appropriate fixes for this directory traversal vulnerability, typically those released after the vulnerability disclosure. Organizations should also implement strict input validation for archive contents, particularly when processing untrusted archives, by employing tools that sanitize file paths before extraction occurs. The implementation of secure extraction practices includes running tar extraction processes with minimal privileges, restricting write permissions to specific directories, and employing sandboxing techniques to contain potential file system modifications. Additionally, system administrators should consider implementing automated monitoring for suspicious file system changes that might indicate exploitation attempts, as well as maintaining current threat intelligence on similar vulnerabilities within the tar utility and related archive processing tools. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and persistence through file system manipulation, emphasizing the need for comprehensive security controls that address both the immediate vulnerability and broader system exposure risks.