CVE-2017-10672 in XML-LibXML
Summary
by MITRE
Use-after-free in the XML-LibXML module through 2.0129 for Perl allows remote attackers to execute arbitrary code by controlling the arguments to a replaceChild call.
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Analysis
by VulDB Data Team • 12/09/2022
The vulnerability identified as CVE-2017-10672 represents a critical use-after-free flaw within the XML-LibXML Perl module version 2.0129 and earlier. This vulnerability specifically manifests in the replaceChild function call where an attacker can manipulate input arguments to trigger a memory management error that results in arbitrary code execution. The flaw exists at the intersection of memory safety and XML processing, creating a dangerous attack surface where malformed XML input can be exploited to compromise systems running vulnerable versions of the module.
The technical root cause of this vulnerability stems from improper memory management within the XML-LibXML module's implementation of the replaceChild method. When processing XML documents containing crafted malicious input, the module fails to properly validate or sanitize the arguments passed to the replaceChild function, leading to a situation where freed memory locations are accessed after the original memory has been deallocated. This use-after-free condition creates a predictable memory corruption scenario that attackers can leverage to execute arbitrary code with the privileges of the affected process. The vulnerability is classified under CWE-416 as a Use After Free condition, which is a well-known class of memory safety issues that frequently leads to remote code execution in software libraries.
The operational impact of CVE-2017-10672 extends beyond simple code execution, as it represents a severe remote attack vector that can be exploited without authentication. Attackers can craft malicious XML documents that, when processed by applications using vulnerable versions of XML-LibXML, trigger the memory corruption. This vulnerability affects any system that relies on Perl applications using the XML-LibXML module for XML processing, including web applications, content management systems, and enterprise software solutions. The attack surface is particularly broad given Perl's widespread use in web development and system administration tasks where XML processing is common.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, as the arbitrary code execution capability allows attackers to run malicious commands on compromised systems. Additionally, the vulnerability demonstrates characteristics of T1190 for Exploit Public-Facing Application, as it can be leveraged through applications that expose XML processing capabilities to untrusted input. Organizations running vulnerable systems face significant risk of data breaches, system compromise, and potential lateral movement within their networks. The vulnerability's remote nature means that attackers can exploit it from outside the network perimeter, making it particularly dangerous for publicly accessible applications and services.
Mitigation strategies for CVE-2017-10672 focus primarily on immediate remediation through version updates to XML-LibXML 2.0130 or later, which contain the necessary memory management fixes. Organizations should conduct comprehensive inventory assessments to identify all systems running vulnerable versions of the module and prioritize patching efforts accordingly. Network segmentation and input validation measures can provide additional defense-in-depth layers, while monitoring systems should be configured to detect unusual XML processing patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of keeping third-party libraries updated and maintaining robust security practices for Perl applications that handle XML data processing.