CVE-2023-2798
📋 TL;DR
HtmlUnit versions before 2.70.0 contain a stack overflow vulnerability when processing untrusted web content, allowing denial of service attacks. This affects applications that use HtmlUnit to browse or render user-supplied web pages. The vulnerability can cause the HtmlUnit process to crash, disrupting service availability.
💻 Affected Systems
- HtmlUnit
📦 What is this software?
Htmlunit by Htmlunit
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption through process crashes, potentially affecting application availability and requiring manual intervention to restart services.
Likely Case
Intermittent service disruptions when processing malicious content, leading to degraded performance and potential data loss in user sessions.
If Mitigated
Minimal impact with proper input validation and resource limits, though some performance degradation may still occur.
🎯 Exploit Status
Exploitation requires ability to supply web content to HtmlUnit. The fuzzing test case is publicly available in the OSS-Fuzz issue.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.70.0
Vendor Advisory: https://github.com/HtmlUnit/htmlunit/commit/940dc7fd
Restart Required: Yes
Instructions:
1. Update HtmlUnit dependency to version 2.70.0 or later. 2. Update pom.xml or build.gradle to specify the new version. 3. Rebuild and redeploy the application. 4. Restart any running services using HtmlUnit.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict validation of user-supplied URLs and web content before passing to HtmlUnit.
Resource Limiting
allConfigure JVM stack size limits and implement timeout mechanisms for HtmlUnit operations.
-Xss256k (reduce JVM thread stack size)
Set WebClient.setTimeout() to reasonable limits
🧯 If You Can't Patch
- Isolate HtmlUnit usage to separate processes with automatic restart capabilities
- Implement strict content filtering and URL allowlisting for HtmlUnit inputs
🔍 How to Verify
Check if Vulnerable:
Check the HtmlUnit version in your project dependencies. If using Maven: mvn dependency:tree | grep htmlunit. If using Gradle: gradle dependencies | grep htmlunit.Check Version:
java -cp "htmlunit-*.jar" com.gargoylesoftware.htmlunit.WebClient --version 2>/dev/null || echo "Check pom.xml/gradle.build for version"Verify Fix Applied:
Verify the HtmlUnit version is 2.70.0 or higher in your dependency management file and built artifacts.📡 Detection & Monitoring
Log Indicators:
- StackOverflowError exceptions in logs
- HtmlUnit process crashes
- Abnormal termination of web scraping/services
Network Indicators:
- Unusual patterns of web content submission
- Repeated requests with similar malicious payloads
SIEM Query:
source="application.logs" AND ("StackOverflowError" OR "HtmlUnit" AND "crash")