CVE-2012-0880 in Xerces-C++
Summary
by MITRE
Apache Xerces-C++ allows remote attackers to cause a denial of service (CPU consumption) via a crafted message sent to an XML service that cause hash table collisions.
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Analysis
by VulDB Data Team • 03/04/2025
The vulnerability identified as CVE-2012-0880 affects Apache Xerces-C++ an open source library for parsing xml documents and validating xml schemas. This flaw represents a significant security concern as it allows remote attackers to exploit a denial of service condition through carefully crafted xml messages that specifically target the library's hash table implementation. The vulnerability resides within the xml parsing engine where hash table collisions occur during the processing of malformed xml content, leading to excessive cpu consumption and ultimately service disruption.
The technical implementation of this vulnerability stems from the hash table collision handling mechanism within the xerces-c++ parser. When processing xml content containing specially crafted elements or attributes, the parser's internal hash table structures experience collision patterns that cause the hash table to degrade from optimal O(1) lookup time to O(n) performance characteristics. This degradation occurs because the parser uses a hash table to store and retrieve xml element names, attribute names, and other metadata during parsing operations. When attackers send xml messages designed to create hash collisions, the parser's performance degrades significantly as it must resolve these collisions through linear probing or other collision resolution mechanisms, consuming excessive cpu cycles and potentially leading to system resource exhaustion.
The operational impact of CVE-2012-0880 extends beyond simple service disruption as it can affect any application or service that relies on xerces-c++ for xml processing including web applications, enterprise systems, and xml-based communication protocols. Attackers can exploit this vulnerability by sending malicious xml messages to xml services that utilize the affected library, causing the target system to consume excessive cpu resources and potentially leading to complete service unavailability. The vulnerability is particularly dangerous because it requires minimal privileges to exploit and can be triggered through normal xml processing operations without requiring authentication or special access rights. This makes it an attractive vector for denial of service attacks against xml-based services and applications.
This vulnerability aligns with CWE-400 which classifies the issue as a resource exhaustion condition, specifically related to hash table collision attacks. The attack pattern follows the methodology described in the attack tree framework where an adversary can exploit weaknesses in data structure implementations to cause resource exhaustion. The vulnerability also relates to the broader category of algorithmic complexity attacks that target hash table implementations and can be categorized under the attack techniques described in the mitre att&ck framework for resource exhaustion and denial of service operations. Organizations using xerces-c++ should implement input validation and xml parsing restrictions to mitigate the risk of this vulnerability.
Mitigation strategies for CVE-2012-0880 include upgrading to patched versions of Apache Xerces-C++ where the hash table collision handling has been improved to prevent excessive cpu consumption. Additionally, organizations should implement xml input validation and size limits on incoming xml content to prevent exploitation. Network level protections such as xml firewalls or api gateways can help filter malicious xml content before it reaches vulnerable applications. The implementation of rate limiting and resource monitoring can help detect and prevent exploitation attempts. System administrators should also consider implementing intrusion detection systems that can identify unusual cpu consumption patterns associated with hash table collision attacks. Regular security assessments and vulnerability scanning should include checks for the presence of vulnerable xerces-c++ versions to ensure comprehensive protection against this specific denial of service vulnerability.