CVE-2004-1575 in Xerces-C++
Summary
by MITRE
The XML parser in Xerces-C++ 2.5.0 allows remote attackers to cause a denial of service (CPU consumption) via XML attributes in a crafted XML document.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/30/2021
The vulnerability identified as CVE-2004-1575 represents a critical denial of service flaw within the Xerces-C++ XML parser version 2.5.0. This vulnerability specifically targets the parser's handling of XML attributes within maliciously crafted XML documents, enabling remote attackers to consume excessive CPU resources and potentially disrupt system availability. The issue stems from the parser's inefficient processing of certain attribute structures that trigger recursive or iterative operations, leading to disproportionate resource consumption. This vulnerability falls under the category of resource exhaustion attacks and demonstrates how XML parsing libraries can be exploited to create system instability through carefully constructed input data. The flaw impacts systems that rely on Xerces-C++ for XML processing, particularly those handling untrusted input from external sources.
The technical implementation of this vulnerability exploits the parser's attribute processing logic by constructing XML documents containing specially formatted attributes that cause the parser to enter computationally expensive processing loops. When the parser encounters these malformed attributes, it attempts to validate and process them in ways that consume significant CPU cycles without proper bounds checking or resource limits. The flaw typically manifests through attribute value processing where certain character sequences or attribute structures trigger recursive parsing behaviors that escalate CPU usage exponentially. This behavior aligns with CWE-400, which categorizes the vulnerability as an unspecified vulnerability related to resource exhaustion, and demonstrates how XML parsers can be manipulated to create denial of service conditions through attribute manipulation. The parser's failure to implement adequate input validation and resource consumption limits creates an environment where malicious input can cause sustained high CPU utilization.
The operational impact of CVE-2004-1575 extends beyond simple service disruption to potentially compromise system stability and availability across multiple applications. Systems utilizing Xerces-C++ for XML processing become vulnerable to attacks that can consume entire CPU cores or memory resources, making them susceptible to distributed denial of service scenarios. This vulnerability particularly affects web applications, middleware systems, and any software that processes XML data from untrusted sources, including web services, content management systems, and enterprise applications. Attackers can exploit this vulnerability by submitting crafted XML documents containing malicious attributes to services that rely on Xerces-C++ for parsing, resulting in sustained high CPU usage that can render systems unresponsive or cause cascading failures in networked environments. The vulnerability's impact is amplified in environments where multiple XML parsing operations occur simultaneously, as the resource exhaustion can affect entire application servers or service clusters.
Mitigation strategies for CVE-2004-1575 should focus on both immediate remediation and long-term architectural improvements to prevent similar vulnerabilities. The primary solution involves upgrading to a patched version of Xerces-C++ that addresses the attribute processing flaw and implements proper bounds checking for resource consumption. Organizations should also implement input validation measures that filter or sanitize XML attributes before processing, particularly focusing on limiting attribute value length and complexity. Network-level protections such as rate limiting, XML size restrictions, and content filtering can help prevent exploitation attempts from reaching vulnerable systems. Additionally, implementing proper resource monitoring and alerting systems allows administrators to detect unusual CPU consumption patterns that may indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving resource exhaustion and denial of service, requiring defensive measures that align with the adversary's attack patterns. Organizations should also consider implementing application-level firewalls or XML gateways that can detect and block suspicious attribute structures before they reach the vulnerable parser, providing an additional layer of protection against exploitation attempts.