CVE-2008-4779 in Tguzip
Summary
by MITRE
Stack-based buffer overflow in TUGzip 3.5.0.0 allows remote attackers to denial of service (crash) or execute arbitrary code via a long filename in a .zip file.
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Analysis
by VulDB Data Team • 05/25/2025
The vulnerability identified as CVE-2008-4779 represents a critical stack-based buffer overflow flaw within TUGzip version 3.5.0.0, a widely used compression utility for handling zip archives. This vulnerability exists in the file extraction process where the software fails to properly validate the length of filenames contained within zip archives before attempting to copy them into fixed-size stack buffers. The flaw specifically manifests when processing zip files containing excessively long filenames that exceed the allocated buffer space, creating a condition where adjacent memory locations become overwritten with attacker-controlled data. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows for memory corruption. The vulnerability is particularly dangerous because it can be exploited remotely through malicious zip files, making it a significant threat vector for both denial of service attacks and arbitrary code execution.
The technical implementation of this vulnerability occurs during the decompression process when TUGzip encounters a zip file with a filename that exceeds the predetermined buffer size allocated on the stack. The software performs a simple string copy operation without validating the source length against the destination buffer capacity, allowing a buffer overflow condition to occur. When an attacker crafts a zip file containing a filename that is longer than the allocated stack buffer, the excess data overflows into adjacent memory locations, potentially corrupting the stack frame and control structures. This memory corruption can result in program termination through segmentation faults or more critically, allow attackers to manipulate the instruction pointer to redirect execution flow to malicious code injected into the overflowed memory regions. The vulnerability's exploitability is enhanced by the fact that zip file processing is a common operation that occurs automatically when users open or extract archives, making it difficult to defend against through simple user awareness.
From an operational impact perspective, this vulnerability creates significant risk for organizations relying on TUGzip for file management and archive handling. The potential for remote code execution means that attackers could gain full system control when victims open maliciously crafted zip files, particularly in environments where automated archive extraction occurs or where users frequently handle untrusted files. The denial of service aspect alone can cause system instability and service disruption, as the application crashes when processing malformed zip files. This vulnerability affects both individual users and enterprise environments where zip file handling is part of routine operations, potentially compromising entire networks through targeted attacks on specific systems. The attack surface extends beyond simple user interaction to include web applications that process zip files, email attachments, and automated file processing systems that may be vulnerable to exploitation.
Mitigation strategies for CVE-2008-4779 should focus on immediate software updates and system hardening measures. The most effective solution involves upgrading to a patched version of TUGzip that implements proper input validation and bounds checking for filename lengths. Organizations should also implement network-level filtering to prevent the delivery of potentially malicious zip files through email attachments and web downloads. Input sanitization measures including maximum filename length restrictions and proper buffer overflow protection mechanisms should be implemented at multiple layers of the system architecture. Security professionals should consider implementing application whitelisting policies that restrict execution of known vulnerable applications and deploy intrusion detection systems to monitor for exploitation attempts. Additionally, regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable software within the organization's infrastructure. The vulnerability demonstrates the importance of proper software security practices including input validation, buffer management, and regular security updates to prevent exploitation of known vulnerabilities. Organizations should also consider implementing security awareness training to help users recognize potentially malicious zip files and avoid opening untrusted archives.