CVE-2025-50681 is a denial-of-service vulnerability found in igmpproxy versions prior to commit 2b30c36. The root cause is insufficient input validation in the recv_igmp() function within src/igmpproxy.c, specifically when handling IGMPv3 membership report packets. An attacker can send a crafted IGMPv3 packet containing an invalid group record type with a malicious source address. When igmpproxy attempts to log this malformed packet using the inet_fmtsrc() function, it triggers a NULL pointer dereference, causing the application to crash. Since igmpproxy is widely deployed in embedded networking environments and consumer-grade IoT devices, including home routers and media gateways that manage multicast traffic for IPTV and streaming services, this vulnerability can be exploited remotely over a local area network without requiring authentication or user interaction. The crash results in a denial of service, disrupting multicast traffic handling and potentially affecting network availability. Although no public exploits have been reported, the vulnerability’s CVSS 3.1 base score of 7.5 reflects its high severity due to ease of exploitation and impact on availability. The vulnerability is categorized under CWE-120 (Classic Buffer Overflow), indicating a memory safety issue. No official patches are linked yet, so affected organizations must monitor vendor updates closely.

For European organizations, the primary impact is the disruption of multicast traffic services such as IPTV and streaming that rely on igmpproxy-enabled devices. Denial of service can lead to network outages or degraded service quality, affecting business operations, customer experience, and potentially critical communications in enterprise or service provider environments. The vulnerability affects embedded devices commonly used in home and small office networks, which are often less rigorously managed, increasing the risk of exploitation. In sectors like telecommunications, media, and utilities that use multicast streaming extensively, service interruptions could have broader operational and reputational consequences. Additionally, the attack can be launched remotely over LAN without authentication, making it easier for internal or adjacent network attackers to cause disruption. While confidentiality and integrity are not directly impacted, availability degradation can indirectly affect business continuity and service-level agreements. Organizations with large deployments of vulnerable IoT or networking devices should consider this a significant risk to network stability.

Organizations should first identify all devices running vulnerable versions of igmpproxy, especially embedded routers, media gateways, and IoT devices handling multicast traffic. Since no official patches are currently linked, network administrators should monitor vendor advisories for updates or firmware releases addressing this issue. In the interim, network segmentation can limit exposure by isolating multicast traffic and restricting access to devices running igmpproxy from untrusted or less secure network segments. Implementing strict multicast traffic filtering and validation at network ingress points can help block malformed IGMPv3 packets that could trigger the vulnerability. Network intrusion detection systems (NIDS) should be configured to alert on suspicious IGMPv3 membership reports. Device hardening practices, including disabling unnecessary multicast services where possible, can reduce the attack surface. Regularly updating device firmware and maintaining an inventory of IoT devices will facilitate timely remediation once patches become available. Finally, organizations should prepare incident response plans to quickly address potential denial-of-service incidents affecting multicast services.