CVE-2007-4134 in Fedora
Summary
by MITRE
Directory traversal vulnerability in extract.c in star before 1.5a84 allows user-assisted remote attackers to overwrite arbitrary files via certain //.. (slash slash dot dot) sequences in directory symlinks in a TAR archive.
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Analysis
by VulDB Data Team • 06/07/2025
The vulnerability identified as CVE-2007-4134 represents a critical directory traversal flaw within the star archiving utility, specifically affecting versions prior to 1.5a84. This issue resides in the extract.c component of the software, where improper handling of directory symlinks in TAR archives creates a pathway for malicious exploitation. The vulnerability manifests when processing certain //.. (slash slash dot dot) sequences that appear within directory symlinks, enabling attackers to manipulate file paths in unintended ways. The flaw operates at the archive extraction level, where the software fails to properly validate or sanitize symlink paths during decompression operations.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the star utility's extraction logic. When processing TAR archives containing maliciously crafted symlinks with //.. sequences, the software does not sufficiently normalize or sanitize these path references before attempting file operations. This allows an attacker to construct archive contents that, when extracted, can traverse the filesystem beyond the intended extraction directory. The vulnerability specifically exploits the way the utility handles directory navigation sequences, where the double slash followed by dot-dot components can be interpreted as a means to move up directory hierarchies regardless of the current extraction context. This behavior directly violates proper path validation principles and creates opportunities for arbitrary file overwrite operations.
The operational impact of CVE-2007-4134 extends beyond simple file corruption, as it enables attackers to potentially overwrite critical system files, configuration data, or files belonging to other users. An attacker with the ability to influence or upload TAR archives to a system running vulnerable star versions can execute remote code execution through file overwrite attacks, particularly targeting system binaries or configuration files. The vulnerability is classified as user-assisted remote, meaning that successful exploitation requires the victim to perform an action such as extracting a malicious archive, but the attack can be initiated from remote locations. This makes it particularly dangerous in environments where users may download and extract archives from untrusted sources, such as web applications, automated build systems, or file sharing platforms. The vulnerability has implications for various attack vectors including web application exploitation, supply chain attacks, and privilege escalation scenarios.
Mitigation strategies for this vulnerability center on immediate software updates to versions 1.5a84 or later, where the directory traversal protection mechanisms have been implemented. Organizations should conduct comprehensive vulnerability assessments to identify systems running vulnerable versions of star and ensure all instances are updated promptly. Additionally, implementing proper access controls and restricting write permissions for archive extraction directories can limit the potential damage from successful exploitation attempts. System administrators should consider deploying automated monitoring solutions to detect unusual file modification patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and maps to ATT&CK technique T1059.007 for command and scripting interpreter usage, particularly in scenarios involving archive extraction and file manipulation operations. Organizations should also implement secure coding practices that emphasize proper input validation, path normalization, and privilege separation when handling archive extraction operations to prevent similar vulnerabilities from emerging in other software components.