CVE-2016-0729 in PeopleSoft Enterprise PeopleTools
Summary
by MITRE
Multiple buffer overflows in (1) internal/XMLReader.cpp, (2) util/XMLURL.cpp, and (3) util/XMLUri.cpp in the XML Parser library in Apache Xerces-C before 3.1.3 allow remote attackers to cause a denial of service (segmentation fault or memory corruption) or possibly execute arbitrary code via a crafted document.
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Analysis
by VulDB Data Team • 11/02/2024
The vulnerability CVE-2016-0729 represents a critical security flaw in Apache Xerces-C, a widely-used XML parser library that forms the foundation for numerous applications including web browsers, enterprise software, and security tools. This vulnerability manifests through multiple buffer overflow conditions affecting three core components of the XML parsing engine: internal/XMLReader.cpp, util/XMLURL.cpp, and util/XMLUri.cpp. The flaw exists in versions prior to 3.1.3 and enables remote attackers to exploit the parser through carefully crafted XML documents, potentially leading to catastrophic system compromise.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the XML parsing routines. When processing malformed XML documents, the parser fails to properly bounds-check buffer allocations during URL and URI parsing operations, creating opportunities for attackers to overwrite adjacent memory locations. This buffer overflow condition occurs specifically during the parsing of certain URI schemes and URL constructs within XML documents, where the parser attempts to store data exceeding allocated buffer boundaries. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, and aligns with ATT&CK technique T1203 for exploitation of memory corruption vulnerabilities.
The operational impact of CVE-2016-0729 extends beyond simple denial of service scenarios to potentially enable remote code execution. Attackers can craft malicious XML documents that trigger segmentation faults or memory corruption during parsing, which may result in system crashes or, more critically, allow arbitrary code execution if proper exploitation techniques are applied. The affected components process various XML constructs including URLs and URIs, making this vulnerability particularly dangerous in web applications, content management systems, and any software that processes untrusted XML input. The vulnerability affects not only the Apache Xerces-C library itself but also any applications that depend on it, creating a widespread attack surface across numerous software ecosystems.
Mitigation strategies for this vulnerability require immediate patching of all affected Apache Xerces-C installations to version 3.1.3 or later, which includes proper buffer bounds checking and memory management improvements. Organizations should implement input validation measures to filter potentially malicious XML content before processing, particularly when handling external input sources. Network segmentation and application firewalls can help limit the attack surface by restricting access to XML processing endpoints. Additionally, security monitoring should be enhanced to detect unusual patterns in XML parsing operations that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of robust memory safety practices in parsing libraries, as XML parsers are frequently targeted due to their role in processing untrusted data from diverse sources including web applications, email systems, and database inputs.