CVE-2013-4420 in libtar
Summary
by MITRE
Multiple directory traversal vulnerabilities in the (1) tar_extract_glob and (2) tar_extract_all functions in libtar 1.2.20 and earlier allow remote attackers to overwrite arbitrary files via a .. (dot dot) in a crafted tar file.
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Analysis
by VulDB Data Team • 12/25/2024
The vulnerability identified as CVE-2013-4420 represents a critical directory traversal flaw within the libtar library version 1.2.20 and earlier implementations. This security issue affects the tar_extract_glob and tar_extract_all functions that are commonly used for extracting tar archive files within various software applications. The vulnerability stems from insufficient input validation and path handling mechanisms that fail to properly sanitize file paths contained within tar archives, creating an avenue for malicious actors to manipulate the extraction process.
The technical exploitation of this vulnerability occurs when a maliciously crafted tar file contains directory traversal sequences using the .. (dot dot) notation within file paths. When the vulnerable libtar library processes such archives through the affected functions, it fails to properly validate or sanitize the extracted paths, allowing attackers to specify arbitrary file paths that can overwrite existing files on the target system. This flaw specifically impacts the tar_extract_glob function which handles glob pattern matching during extraction, and the tar_extract_all function that processes complete archive extractions, both of which are widely used in Unix-like systems and applications that handle tar archives.
The operational impact of CVE-2013-4420 extends beyond simple file overwrites to potentially enable more sophisticated attack vectors including privilege escalation, system compromise, and denial of service conditions. Attackers can leverage this vulnerability to overwrite critical system files, configuration files, or even binaries that are part of the system's core functionality. The vulnerability aligns with CWE-22 Directory Traversal and CWE-352 Cross-Site Request Forgery categories, representing a classic path traversal attack that has been a persistent threat in file handling systems. From an ATT&CK framework perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1078 Valid Accounts, as it can be used to establish persistence or escalate privileges through file system manipulation.
The exploitation of this vulnerability requires minimal technical sophistication and can be automated through various attack frameworks, making it particularly dangerous in environments where tar archives are processed without proper validation. System administrators and developers using libtar versions prior to 1.2.21 should prioritize immediate remediation, as the vulnerability affects numerous applications including package managers, backup systems, and automated deployment tools. The recommended mitigation strategy involves upgrading to libtar version 1.2.21 or later, implementing proper input validation for archive file paths, and configuring applications to run with minimal privileges during archive processing operations. Additionally, organizations should implement network segmentation and monitoring controls to detect suspicious archive extraction activities that may indicate exploitation attempts.