CVE-2004-0941 in Secure Linux
Summary
by MITRE
Multiple buffer overflows in the gd graphics library (libgd) 2.0.21 and earlier may allow remote attackers to execute arbitrary code via malformed image files that trigger the overflows due to improper calls to the gdMalloc function, a different set of vulnerabilities than CVE-2004-0990.
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Analysis
by VulDB Data Team • 06/05/2019
The vulnerability described in CVE-2004-0941 represents a critical security flaw within the gd graphics library version 2.0.21 and earlier implementations. This library serves as a fundamental component for image processing in numerous web applications and server environments, making it a prime target for exploitation. The vulnerability stems from multiple buffer overflow conditions that occur when the library processes malformed image files, specifically those that manipulate the internal memory allocation mechanisms. These buffer overflows are particularly dangerous because they can be triggered remotely through crafted image inputs, allowing attackers to potentially execute arbitrary code on vulnerable systems. The flaw specifically involves improper handling of memory allocation calls to the gdMalloc function, which is responsible for allocating memory blocks for image data processing. When the library encounters malformed image data, these improper memory allocation calls result in memory corruption that can be exploited to gain control over the executing process.
The technical exploitation of this vulnerability leverages the fundamental weakness in memory management within the gd graphics library. Attackers can construct specially crafted image files that, when processed by the vulnerable library, cause the gdMalloc function to allocate insufficient memory for expected data structures. This leads to buffer overflows where data written beyond allocated memory boundaries can overwrite critical program variables, return addresses, or function pointers. The exploitation typically requires precise control over the overflowed memory regions to redirect program execution flow, often through stack-based buffer overflows that allow attackers to inject and execute malicious code. The vulnerability is particularly concerning because it affects the core image processing functionality that many web applications rely upon, including content management systems, image upload features, and web-based graphics applications. This makes the attack surface extensive and increases the potential impact across various software platforms that depend on libgd for image handling operations.
The operational impact of CVE-2004-0941 extends far beyond individual system compromises, as it affects the broader ecosystem of web applications and server environments that utilize the gd graphics library. When exploited successfully, these buffer overflows can lead to complete system compromise, allowing attackers to execute arbitrary commands with the privileges of the affected application process. This could result in unauthorized data access, system infiltration, and potential lateral movement within network environments. The vulnerability's remote exploitability means that attackers do not need physical access to target systems, making it particularly dangerous for publicly accessible web applications. Organizations running vulnerable versions of libgd may experience service disruption, data breaches, and compliance violations, especially in regulated environments where image processing capabilities are critical. The impact is further amplified by the widespread adoption of gd library across numerous software platforms, meaning that a single vulnerability can affect multiple applications and systems simultaneously. This vulnerability aligns with CWE-121 and CWE-122 categories related to stack-based and heap-based buffer overflows, and represents a classic example of how memory safety issues in core libraries can create cascading security risks throughout software ecosystems.
The remediation approach for CVE-2004-0941 requires immediate upgrading to libgd versions 2.0.22 or later, which contain patches addressing the buffer overflow conditions in memory allocation handling. System administrators should conduct comprehensive vulnerability assessments to identify all systems running affected versions of the library, particularly those with web-facing applications that process user-uploaded images. Additionally, implementing proper input validation and sanitization measures for image file processing can provide defense-in-depth protection against similar vulnerabilities. The mitigation strategy should include network segmentation to limit exposure of vulnerable applications, deployment of intrusion detection systems to monitor for exploitation attempts, and regular security updates to maintain protection against emerging threats. Organizations should also consider implementing application whitelisting controls and restricting write permissions for image processing directories to minimize the impact of successful exploitation attempts. This vulnerability demonstrates the critical importance of maintaining up-to-date third-party libraries and implementing robust security practices in software development and deployment environments. The issue relates to ATT&CK technique T1190 for exploitation through malicious files and T1059 for command execution, highlighting the multi-stage nature of attacks that leverage such fundamental library vulnerabilities. Regular security audits and vulnerability management processes are essential to prevent similar issues from compromising system integrity and maintaining overall security posture against evolving threat landscapes.