CVE-2005-1211 in Internet Explorer
Summary
by MITRE
Buffer overflow in the PNG image rendering component of Microsoft Internet Explorer allows remote attackers to execute arbitrary code via a crafted PNG file.
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability identified as CVE-2005-1211 represents a critical buffer overflow flaw within Microsoft Internet Explorer's handling of Portable Network Graphics image files. This security weakness resides in the PNG rendering component that processes image data when web pages are displayed in the browser environment. The flaw manifests when Internet Explorer encounters a specially crafted PNG file that contains malformed data structures designed to exceed the allocated memory buffers during image processing operations. Such buffer overflows typically occur when programs fail to properly validate input data lengths before copying them into fixed-size memory buffers, creating opportunities for attackers to overwrite adjacent memory locations with malicious code sequences.
The technical implementation of this vulnerability leverages the inherent characteristics of the PNG file format and how Internet Explorer's rendering engine processes these images. When a user visits a web page containing a maliciously constructed PNG image or when such an image is loaded through embedded content, the browser's PNG decoder attempts to parse the image data without adequate bounds checking. The buffer overflow occurs during the decompression or parsing phase of PNG image processing, where the application allocates insufficient memory space for the image data. Attackers can exploit this by crafting a PNG file with oversized metadata fields or malformed image dimensions that cause the rendering engine to write beyond the intended buffer boundaries. This overflow can overwrite critical memory areas including return addresses on the stack, allowing attackers to redirect program execution flow to malicious code.
The operational impact of CVE-2005-1211 is severe and potentially catastrophic for affected systems. Remote code execution capabilities enable attackers to gain complete control over vulnerable systems without requiring any local privileges or user interaction beyond visiting a malicious webpage. This vulnerability affects Microsoft Internet Explorer versions prior to the security updates released in 2005, making it particularly dangerous as Internet Explorer was the dominant web browser at the time. The exploit can be delivered through various attack vectors including malicious websites, email attachments, or compromised web servers, making it highly scalable and dangerous for enterprise environments. Organizations using older versions of Internet Explorer faced significant risks, as the vulnerability could be leveraged for full system compromise, data exfiltration, and persistence mechanisms that would allow attackers to maintain access over extended periods.
The vulnerability aligns with CWE-121, which describes buffer overflow conditions where insufficient space is allocated for data, and represents a classic stack-based buffer overflow scenario. From an adversarial perspective, this flaw maps directly to ATT&CK technique T1203, involving exploitation of web applications for remote code execution, and T1059, covering command and scripting interpreters for execution. Microsoft addressed this vulnerability through security patches that implemented proper bounds checking in the PNG rendering component and introduced additional input validation mechanisms. Organizations should have implemented immediate mitigations including browser updates, network-based filtering of PNG content, and user education about avoiding untrusted web content. The incident highlighted the critical importance of proper input validation and memory safety practices in web browser implementations, influencing subsequent security development lifecycle improvements and leading to more robust handling of image formats in modern browser architectures.