CVE-2003-1048 in Internet Explorer
Summary
by MITRE
Double free vulnerability in mshtml.dll for certain versions of Internet Explorer 6.x allows remote attackers to cause a denial of service (application crash) via a malformed GIF image.
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Analysis
by VulDB Data Team • 01/02/2025
The vulnerability identified as CVE-2003-1048 represents a critical double free condition within the mshtml.dll component of Internet Explorer 6.x versions, specifically affecting the handling of malformed GIF image data. This flaw resides in the HTML parsing and rendering engine of Microsoft's web browser, where the mshtml.dll library is responsible for processing various web content including images. The double free vulnerability occurs when the application attempts to release the same memory block twice, which can lead to unpredictable behavior and system instability. The issue is particularly concerning because it can be triggered remotely through a specially crafted GIF image file, making it an attractive target for attackers seeking to disrupt web services or compromise user systems.
From a technical perspective, this vulnerability operates at the memory management level within the browser's rendering pipeline, where the mshtml.dll component processes image data structures. When a malformed GIF image is encountered, the parsing logic fails to properly manage memory allocation and deallocation sequences, resulting in the same memory chunk being freed twice. This memory corruption scenario can be exploited by remote attackers who craft malicious GIF files designed to trigger the specific code path that leads to the double free condition. The vulnerability is classified under CWE-415 as an "Double Free" which is a well-known weakness in memory management that can lead to arbitrary code execution or denial of service conditions.
The operational impact of CVE-2003-1048 extends beyond simple application crashes, as it can be leveraged in broader attack scenarios within the context of the ATT&CK framework's defense evasion and execution tactics. While the primary effect manifests as a denial of service through application crashes, the underlying memory corruption presents opportunities for more sophisticated attacks including privilege escalation or remote code execution depending on the execution environment and additional vulnerabilities present. The vulnerability affects a significant portion of internet users during the era when Internet Explorer 6.x was prevalent, as it requires no user interaction beyond visiting a malicious website or opening a compromised email attachment containing the malicious GIF image. This makes it particularly dangerous in enterprise environments where users may inadvertently encounter such content through phishing campaigns or compromised web services.
Mitigation strategies for CVE-2003-1048 primarily focus on immediate patching and system hardening measures. Microsoft released security updates addressing this vulnerability through their regular security bulletins, and organizations should prioritize applying these patches to prevent exploitation. Additional protective measures include implementing web content filtering solutions that can identify and block malformed image content, configuring browser security settings to restrict image loading from untrusted sources, and employing network-based intrusion detection systems that can monitor for patterns consistent with exploitation attempts. The vulnerability highlights the importance of proper memory management practices in software development and demonstrates how seemingly benign image processing can become a vector for serious security incidents. Organizations should also consider implementing application whitelisting policies and using sandboxing techniques to limit the potential impact of such vulnerabilities, aligning with ATT&CK's recommendations for reducing attack surface and limiting privilege escalation opportunities.