CVE-2016-4570 in mxml
Summary
by MITRE
The mxmlDelete function in mxml-node.c in mxml 2.9, 2.7, and possibly earlier allows remote attackers to cause a denial of service (stack consumption) via crafted xml file.
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Analysis
by VulDB Data Team • 11/11/2022
The vulnerability identified as CVE-2016-4570 resides within the mxml library version 2.9 and 2.7, with potential exposure in earlier releases, specifically targeting the mxmlDelete function located in mxml-node.c. This flaw represents a classic stack-based buffer overflow condition that can be exploited through maliciously crafted xml input files, creating a remote denial of service scenario that consumes excessive stack memory resources.
The technical implementation of this vulnerability stems from inadequate input validation within the mxmlDelete function which processes xml node structures during memory deallocation operations. When processing malformed xml content, particularly structures containing deeply nested elements or recursive references, the function fails to properly manage stack memory allocation during recursive traversal operations. This deficiency allows attackers to craft xml files that trigger excessive stack consumption through recursive function calls, ultimately leading to stack overflow conditions that crash the application or render it unresponsive.
From an operational perspective, this vulnerability presents significant risk to systems utilizing the mxml library for xml parsing and processing tasks. The remote exploitation capability means that attackers can potentially compromise service availability without requiring local access or authentication. Applications that rely on mxml for configuration file processing, data exchange, or document handling become vulnerable to this denial of service attack, potentially affecting web services, embedded systems, and enterprise applications that process user-provided xml content.
The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions where insufficient bounds checking allows attackers to overwrite stack contents. This classification indicates the fundamental flaw lies in improper memory management during recursive processing operations. From an adversarial perspective, this vulnerability maps to attack techniques described in the MITRE ATT&CK framework under process injection and denial of service tactics, where adversaries leverage software weaknesses to exhaust system resources and disrupt service availability.
Mitigation strategies should prioritize immediate patching of affected mxml library versions to the latest stable releases that contain proper stack management and input validation fixes. Additionally, implementing xml input sanitization measures, establishing stack size limits for parsing operations, and deploying intrusion detection systems to monitor for unusual xml processing patterns can provide defense-in-depth protection. Organizations should also consider implementing xml schema validation and content filtering mechanisms to prevent malformed content from reaching the vulnerable parsing functions, while maintaining regular vulnerability assessment schedules to identify similar memory management issues in other third-party libraries.