CVE-2025-3266
📋 TL;DR
A critical stack-based buffer overflow vulnerability exists in qinguoyi TinyWebServer versions up to 1.0, specifically in the /http/http_conn.cpp file. Attackers can remotely exploit this by manipulating name/password arguments to execute arbitrary code or crash the server. Anyone running TinyWebServer version 1.0 or earlier is affected.
💻 Affected Systems
- qinguoyi TinyWebServer
📦 What is this software?
Tinywebserver by Qinguoyi
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment
Likely Case
Server crash causing denial of service, potentially followed by remote code execution
If Mitigated
Denial of service with limited impact if proper network segmentation and least privilege are implemented
🎯 Exploit Status
Public exploit details available, making weaponization straightforward
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check if you're running TinyWebServer version 1.0 or earlier
2. If vulnerable, immediately stop using TinyWebServer
3. Migrate to alternative web server software
4. No official patch exists from the vendor
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict network access to TinyWebServer to only trusted IP addresses
iptables -A INPUT -p tcp --dport [TinyWebServer_port] -s [trusted_ip] -j ACCEPT
iptables -A INPUT -p tcp --dport [TinyWebServer_port] -j DROP
🧯 If You Can't Patch
- Immediately isolate the vulnerable server from internet access
- Implement strict network segmentation and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check the version of TinyWebServer installed. If version is 1.0 or earlier, you are vulnerable.Check Version:
Check the source code or build information for version numberVerify Fix Applied:
Verify TinyWebServer is no longer running or has been replaced with alternative software📡 Detection & Monitoring
Log Indicators:
- Unusual long strings in name/password fields
- Server crash logs
- Memory access violation errors
Network Indicators:
- Unusually long HTTP requests to authentication endpoints
- Multiple rapid connection attempts
SIEM Query:
source="webserver.log" AND (message="*buffer overflow*" OR message="*segmentation fault*" OR message="*access violation*")🔗 References
- https://magnificent-dill-351.notion.site/Stack-Overflow-in-TinyWebServer-1-0-1c9c693918ed80229bbce911b3513054
- https://vuldb.com/?ctiid.303338
- https://vuldb.com/?id.303338
- https://vuldb.com/?submit.549227
- https://magnificent-dill-351.notion.site/Stack-Overflow-in-TinyWebServer-1-0-1c9c693918ed80229bbce911b3513054
