CVE-2025-50681
📋 TL;DR
CVE-2025-50681 is a remote denial-of-service vulnerability in igmpproxy versions before commit 2b30c36. Attackers can crash the application by sending a crafted IGMPv3 membership report packet with a malicious source address, triggering a NULL pointer dereference. This affects embedded networking devices and consumer IoT products like home routers and media gateways that use igmpproxy for multicast traffic handling.
💻 Affected Systems
- igmpproxy
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of multicast services (IPTV, streaming) on affected devices, requiring manual restart of igmpproxy or device reboot.
Likely Case
Temporary disruption of multicast-dependent services until igmpproxy restarts or device reboots.
If Mitigated
Minimal impact if patched or workarounds implemented; isolated to multicast service disruption.
🎯 Exploit Status
Exploitation requires sending a single malformed IGMPv3 packet to the vulnerable host. Proof-of-concept details are available in public references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 2b30c36 or later
Vendor Advisory: https://github.com/pali/igmpproxy/issues/97
Restart Required: Yes
Instructions:
1. Update igmpproxy to version with commit 2b30c36 or later. 2. Recompile from source if using custom builds. 3. Restart igmpproxy service or reboot device.
🔧 Temporary Workarounds
Disable igmpproxy if not needed
linuxStop and disable the igmpproxy service if multicast functionality is not required.
systemctl stop igmpproxy
systemctl disable igmpproxy
Network filtering
linuxBlock IGMPv3 membership report packets at network boundaries using firewall rules.
iptables -A INPUT -p igmp --igmp-type membership-report -j DROP
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable devices from untrusted networks.
- Monitor for crash events in system logs and set up alerts for igmpproxy service restarts.
🔍 How to Verify
Check if Vulnerable:
Check igmpproxy version: 'igmpproxy -v' or examine source code for commit 2b30c36 presence.Check Version:
igmpproxy -v 2>&1 | head -1Verify Fix Applied:
Verify igmpproxy version is after commit 2b30c36 and test with known exploit packets if possible.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or crash messages in system logs related to igmpproxy
- Unexpected igmpproxy service restarts
Network Indicators:
- IGMPv3 membership report packets with unusual source addresses
- Sudden drop in multicast traffic
SIEM Query:
source="syslog" AND ("igmpproxy" AND ("segmentation fault" OR "crash" OR "SIGSEGV"))