Critical Stack Buffer Overflow Vulnerability in HTMLDOC 1.9.13 (CVE Pending)

Critical Stack Buffer Overflow Flaw Discovered in HTMLDOC 1.9.13

Security researchers have identified a critical stack buffer overflow vulnerability in HTMLDOC 1.9.13, an open-source software used to convert HTML and Markdown files to PDF and PostScript formats. The flaw, disclosed via Exploit-DB, could allow remote attackers to execute arbitrary code on vulnerable systems.

Technical Details

The vulnerability stems from improper bounds checking in HTMLDOC’s input processing. Specifically, the flaw occurs when the software handles maliciously crafted HTML or Markdown files, leading to a stack-based buffer overflow. Attackers can exploit this by tricking users into processing a specially designed file, potentially gaining control over the affected system.

At the time of disclosure, a CVE ID has not yet been assigned, but the exploit code is publicly available, increasing the urgency for organizations to address the issue.

Impact Analysis

• Remote Code Execution (RCE): Successful exploitation could allow attackers to execute arbitrary code with the privileges of the HTMLDOC process.
• Privilege Escalation: If HTMLDOC is run with elevated permissions, attackers may gain higher-level access.
• Supply Chain Risks: Organizations using HTMLDOC in automated document conversion workflows (e.g., web applications, CI/CD pipelines) are particularly vulnerable.

Recommendations

1. Patch or Upgrade: Monitor the HTMLDOC GitHub repository for official patches or updates.
2. Workarounds:
   • Restrict HTMLDOC usage to trusted input sources.
   • Implement sandboxing or containerization to limit potential damage.
3. Monitoring: Deploy intrusion detection systems (IDS) to detect exploitation attempts.
4. User Awareness: Train users to avoid processing untrusted HTML/Markdown files with HTMLDOC.

Security teams should prioritize this vulnerability due to the public availability of exploit code and the potential for severe impact. Further updates will be provided as a CVE ID is assigned and official patches are released.