CVE-2025-29699
📋 TL;DR
NetSurf 3.11 contains a use-after-free vulnerability in the dom_node_set_text_content function that could allow memory corruption. This affects users running NetSurf browser version 3.11. Attackers could potentially exploit this to execute arbitrary code or crash the browser.
💻 Affected Systems
- NetSurf
📦 What is this software?
Netsurf by Netsurf Browser
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if combined with other vulnerabilities or running with elevated privileges.
Likely Case
Browser crash (denial of service) or limited memory corruption that could be leveraged for information disclosure.
If Mitigated
Browser crash with no data loss if running with standard user privileges and proper sandboxing.
🎯 Exploit Status
Proof of concept available in GitHub repository. Exploitation requires user to visit malicious website.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.12 or later
Vendor Advisory: https://www.netsurf-browser.org/news/releases/3.12/
Restart Required: Yes
Instructions:
1. Download NetSurf 3.12 or later from official website. 2. Uninstall current version. 3. Install updated version. 4. Restart browser.
🔧 Temporary Workarounds
Disable JavaScript
allPrevents exploitation by disabling JavaScript execution in NetSurf
Edit netsurf preferences: set 'javascript.enable' to false
Use alternative browser
allTemporarily switch to different browser until patch is applied
🧯 If You Can't Patch
- Restrict browser to trusted websites only using URL filtering
- Run browser with reduced privileges and in sandboxed environment
🔍 How to Verify
Check if Vulnerable:
Check NetSurf version: netsurf --version | grep 'NetSurf'Check Version:
netsurf --version | grep 'NetSurf'Verify Fix Applied:
Verify version is 3.12 or higher: netsurf --version📡 Detection & Monitoring
Log Indicators:
- Browser crash logs with memory access violations
- Segmentation fault errors in system logs
Network Indicators:
- Unusual outbound connections after visiting websites
- Multiple rapid browser crashes
SIEM Query:
process_name:"netsurf" AND (event_type:"crash" OR error:"segmentation fault")