CVE-2004-0797 in zlib
Summary
by MITRE
The error handling in the (1) inflate and (2) inflateBack functions in ZLib compression library 1.2.x allows local users to cause a denial of service (application crash).
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Analysis
by VulDB Data Team • 11/20/2024
The vulnerability identified as CVE-2004-0797 resides within the ZLib compression library version 1.2.x, specifically affecting the inflate and inflateBack functions. This issue represents a classic case of improper error handling that can be exploited by local attackers to induce denial of service conditions. The ZLib library serves as a fundamental component in numerous applications and systems worldwide, providing data compression capabilities that are essential for network protocols, file formats, and system operations. When these core functions fail to properly manage error conditions during decompression processes, they create exploitable pathways that can result in application crashes and system instability.
The technical flaw manifests in how the inflate and inflateBack functions process malformed or corrupted compressed data streams. These functions are designed to handle decompression operations while maintaining robust error detection and recovery mechanisms. However, the implementation contains gaps in error handling logic that allow certain invalid input sequences to trigger unexpected behavior within the decompression engine. When legitimate applications rely on ZLib for decompression tasks and encounter specifically crafted malformed data, the functions fail to properly validate input parameters or handle exceptional conditions, leading to memory corruption or stack overflow conditions that ultimately result in application termination.
The operational impact of this vulnerability extends beyond simple application crashes, as it can affect systems where ZLib is deeply integrated into core infrastructure components. Applications that utilize ZLib for processing user-supplied data, network packet decompression, or file extraction operations become vulnerable to this attack vector. Local users can exploit this weakness by providing specially crafted compressed data that triggers the flawed error handling paths. The consequences include complete service disruption, system instability, and potential denial of service across multiple dependent applications. This vulnerability particularly affects systems where applications perform decompression on untrusted data without proper input validation, making it a significant concern for network services, web applications, and file processing systems that rely on compression libraries.
Mitigation strategies for CVE-2004-0797 primarily involve upgrading to patched versions of the ZLib library where the error handling has been corrected to properly validate input sequences and gracefully handle malformed data. System administrators should prioritize updating all instances of ZLib across affected systems, particularly those running network services or applications that process external data. Additional defensive measures include implementing proper input validation mechanisms, sanitizing compressed data before decompression, and employing sandboxing techniques to isolate decompression operations. From a cybersecurity perspective, this vulnerability aligns with CWE-248, which addresses "Uncaught Exception" conditions, and represents a typical example of how inadequate error handling can lead to system instability. The ATT&CK framework categorizes this as a denial of service attack vector through application-level exploitation, where adversaries leverage software weaknesses to disrupt legitimate system operations and compromise availability. Organizations should also consider implementing network monitoring to detect unusual decompression patterns that might indicate exploitation attempts, while maintaining comprehensive patch management processes to address similar vulnerabilities in related software components.