CVE-2022-34035 in HTMLDoc
Summary
by MITRE • 07/19/2022
HTMLDoc v1.9.12 and below was discovered to contain a heap overflow via e_node htmldoc/htmldoc/html.cxx:588.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/23/2025
The vulnerability identified as CVE-2022-34035 affects HTMLDoc version 1.9.12 and earlier, representing a critical heap overflow condition that arises from improper memory management within the htmldoc library. This issue manifests specifically in the html.cxx source file at line 588, where the e_node structure handling fails to validate input data properly, creating an exploitable condition that can lead to arbitrary code execution or system instability.
The technical flaw stems from a lack of bounds checking when processing HTML document nodes, particularly during the parsing of malformed input data. When the application encounters certain malformed HTML structures, the e_node processing routine attempts to allocate memory on the heap without adequate validation of input parameters, allowing attackers to craft malicious input that exceeds allocated buffer boundaries. This heap overflow condition creates a memory corruption scenario that can be leveraged by adversaries to execute arbitrary code with the privileges of the affected application.
From an operational perspective, this vulnerability presents significant risks to systems that rely on HTMLDoc for document processing, particularly web applications, content management systems, and document conversion services. The impact extends beyond simple application crashes to potentially enable remote code execution, making it a severe concern for organizations that process untrusted HTML input from users or external sources. The vulnerability's exploitation potential aligns with attack patterns documented in the MITRE ATT&CK framework under the T1203 technique for exploitation of remote services and T1059 for command and scripting interpreter usage.
The heap overflow condition creates a predictable memory corruption pattern that can be exploited through carefully crafted input payloads, potentially allowing attackers to overwrite critical memory structures or inject malicious code into the application's memory space. This vulnerability falls under CWE-121, heap-based buffer overflow, and demonstrates poor input validation practices that violate secure coding principles. Organizations utilizing HTMLDoc in production environments must assess their exposure to this vulnerability and implement immediate mitigations to prevent potential exploitation.
Recommended mitigations include upgrading to HTMLDoc version 1.9.13 or later, where the heap overflow has been addressed through proper input validation and memory boundary checks. Additionally, organizations should implement input sanitization measures, restrict HTML input processing to trusted sources, and deploy application-level firewalls or web application firewalls to filter potentially malicious input before it reaches the vulnerable component. The vulnerability highlights the importance of regular security updates and comprehensive code review processes to identify and remediate memory safety issues before they can be exploited in the wild.