CVE-2005-3183 in libwww
Summary
by MITRE
The HTBoundary_put_block function in HTBound.c for W3C libwww (w3c-libwww) allows remote servers to cause a denial of service (segmentation fault) via a crafted multipart/byteranges MIME message that triggers an out-of-bounds read.
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Analysis
by VulDB Data Team • 06/29/2025
The vulnerability identified as CVE-2005-3183 resides within the HTBoundary_put_block function of the HTBound.c component in W3C libwww, a widely used library for HTTP protocol implementation. This flaw represents a classic buffer over-read condition that can be exploited by remote attackers to disrupt service availability. The issue specifically manifests when processing multipart/byteranges MIME messages, which are commonly used in HTTP range requests to retrieve specific portions of a resource. The vulnerability stems from inadequate input validation and boundary checking within the library's MIME parsing logic, creating a scenario where malformed data can trigger unexpected behavior in the application.
The technical exploitation of this vulnerability occurs through a crafted multipart/byteranges MIME message that causes the HTBoundary_put_block function to attempt accessing memory beyond the allocated buffer boundaries. This out-of-bounds read condition leads to a segmentation fault, effectively crashing the target application and resulting in a denial of service. The flaw operates at the protocol parsing layer, making it particularly dangerous as it can be triggered by any HTTP client that sends specially crafted range requests to a vulnerable server. The vulnerability is classified under CWE-125 as an out-of-bounds read, which is a well-documented weakness that allows attackers to read memory locations that should not be accessible, potentially leading to information disclosure or system instability.
From an operational perspective, this vulnerability presents significant risk to web servers and applications that rely on W3C libwww for HTTP processing capabilities. The attack surface is broad as any HTTP server implementing this library becomes potentially vulnerable, particularly those that handle range requests or serve large files where multipart/byteranges is commonly used. The impact extends beyond simple service disruption to include potential information leakage if the out-of-bounds read accesses sensitive memory regions. Security practitioners should consider this vulnerability in the context of ATT&CK technique T1499.004, which covers network denial of service attacks, as the segmentation fault directly results in service unavailability for legitimate users. The vulnerability also aligns with ATT&CK technique T1595.001 related to network scanning and reconnaissance, as attackers may attempt to identify systems using vulnerable versions of the library.
Mitigation strategies for CVE-2005-3183 should prioritize immediate patching of affected systems with updated versions of W3C libwww that contain proper boundary checking and input validation. Organizations should implement network-level protections such as intrusion detection systems that can identify and block malformed multipart/byteranges requests. Application-level defenses include input sanitization measures and proper error handling that prevents segmentation faults from occurring in the first place. Additionally, security teams should consider implementing rate limiting for HTTP range requests and monitoring for unusual patterns of range request processing that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper memory management in network protocol implementations and the necessity of thorough input validation in security-critical code components. Organizations should also conduct inventory checks to identify all systems using vulnerable versions of the library and prioritize remediation based on risk assessment of affected applications.