CVE-2016-9598 in JBoss
Summary
by MITRE
libxml2, as used in Red Hat JBoss Core Services, allows context-dependent attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted XML document. NOTE: this vulnerability exists because of a missing fix for CVE-2016-4483.
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Analysis
by VulDB Data Team • 03/16/2020
The vulnerability identified as CVE-2016-9598 represents a critical out-of-bounds read flaw within libxml2 library versions used in Red Hat JBoss Core Services. This security weakness stems from an incomplete remediation of a previously discovered vulnerability, specifically CVE-2016-4483, which demonstrates the importance of thorough vulnerability patching and validation. The flaw manifests when the xmlParseFile function processes malformed XML documents, creating a scenario where memory access occurs beyond the bounds of allocated buffers.
The technical implementation of this vulnerability involves improper input validation within the XML parsing engine of libxml2. When attackers submit carefully crafted XML documents containing malformed structures or unexpected data sequences, the parser fails to properly bounds-check memory operations during document traversal. This results in the application reading memory locations that are outside the intended buffer boundaries, leading to unpredictable behavior including application crashes and potential information disclosure. The vulnerability operates at the parsing layer where XML documents are interpreted and converted into internal data structures for processing.
From an operational perspective, this vulnerability presents a significant risk to systems utilizing Red Hat JBoss Core Services as it enables context-dependent attackers to execute denial of service attacks. The impact extends beyond simple service disruption as the out-of-bounds read can potentially expose sensitive memory contents or cause application instability that may be exploited further. Attackers can leverage this weakness to crash applications repeatedly, rendering services unavailable to legitimate users and potentially creating opportunities for more sophisticated attacks. The vulnerability's exploitation requires minimal privileges and can be executed through standard XML processing operations.
The remediation approach for CVE-2016-9598 requires immediate application of security patches provided by Red Hat and the libxml2 maintainers. Organizations should prioritize updating their JBoss Core Services installations to versions containing the complete fix for both CVE-2016-9598 and its predecessor CVE-2016-4483. Additionally, implementing XML input validation mechanisms and restricting XML processing to trusted sources can provide defensive measures. Security monitoring should include detection of malformed XML traffic patterns and regular vulnerability scanning of deployed applications to ensure complete remediation of the underlying issue. This vulnerability aligns with CWE-125 out-of-bounds read and represents a typical example of how incomplete vulnerability fixes can leave systems exposed to continued risk.
The broader implications of this vulnerability highlight the critical nature of proper vulnerability management and the dangers of partial remediation. In enterprise environments where JBoss Core Services are extensively deployed, the potential for cascading failures increases significantly when such fundamental parsing libraries contain unpatched flaws. This issue demonstrates the importance of comprehensive testing and validation of security patches, particularly in mission-critical applications where service availability is paramount. Organizations should also consider implementing application-level protections such as input sanitization and memory protection mechanisms to mitigate the impact of similar vulnerabilities in the future. The ATT&CK framework categorizes this as a privilege escalation and denial of service technique, emphasizing the need for layered security approaches to protect against such threats.