CVE-2005-0554 in Internet Explorer
Summary
by MITRE
Buffer overflow in the URL processor of Microsoft Internet Explorer 5.01, 5.5, and 6 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a URL with a long hostname, aka "URL Parsing Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 01/03/2025
The vulnerability identified as CVE-2005-0554 represents a critical buffer overflow flaw within Microsoft Internet Explorer's URL processing mechanism affecting versions 5.01, 5.5, and 6.0. This vulnerability resides in the way the browser handles URL parsing operations when encountering hostnames that exceed predetermined length limits. The flaw manifests when the browser attempts to process a malformed URL containing an excessively long hostname parameter, leading to memory corruption that can result in system instability or complete application crash.
The technical nature of this vulnerability aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking occurs during memory allocation and manipulation. The flaw specifically affects the URL processor component of Internet Explorer, which is responsible for parsing and interpreting web addresses entered by users or encountered during web browsing operations. When processing a URL with an overly long hostname, the application fails to properly validate the input length, allowing memory corruption to occur in the stack-based buffer allocated for hostname storage. This type of vulnerability falls under the ATT&CK framework category of T1203 - Exploitation for Client Execution, as it enables remote code execution through web-based attacks.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution attacks. When exploited successfully, the buffer overflow can overwrite adjacent memory locations, potentially allowing attackers to inject and execute malicious code within the context of the Internet Explorer process. This creates a significant security risk for users who may inadvertently visit compromised websites or receive malicious links through phishing attacks. The vulnerability affects Windows operating systems running the affected Internet Explorer versions and can be exploited through various attack vectors including web pages, email attachments, or malicious websites that craft URLs with deliberately oversized hostname parameters.
Mitigation strategies for CVE-2005-0554 should prioritize immediate patch deployment from Microsoft as the primary defense mechanism, since the vulnerability was addressed through security updates released in 2005. Organizations should implement network-based protections including web application firewalls and URL filtering mechanisms that can detect and block suspicious URL patterns. Browser hardening techniques such as disabling automatic URL processing for untrusted content and implementing strict input validation controls can provide additional layers of protection. Security monitoring should include detection of unusual browser crash patterns and memory corruption events that may indicate exploitation attempts. Users should be educated about the risks of visiting untrusted websites and the importance of keeping browser software updated. The vulnerability demonstrates the critical importance of proper input validation and bounds checking in web browser implementations, as highlighted in industry security best practices and standards such as those defined by the Open Web Application Security Project and NIST cybersecurity guidelines.