CVE-2025-49140 is a high-severity vulnerability affecting the pion/interceptor framework versions 0.1.36 through 0.1.38. Pion Interceptor is a framework used for building RTP/RTCP communication software, commonly employed in real-time media streaming and conferencing applications. The vulnerability arises from improper handling of RTP packet padding length (padLen) in the RTP packet factory component. Specifically, the affected versions do not properly validate that the padding length is greater than zero and less than or equal to the payload length. An attacker can craft malicious RTP packets with manipulated padding length values that trigger a panic condition in the Pion-based Selective Forwarding Unit (SFU), causing the application to crash or become unavailable. This is an example of CWE-770: Allocation of Resources Without Limits or Throttling, where resource exhaustion or improper input validation leads to denial of service. The vulnerability does not impact confidentiality or integrity directly but results in a high impact on availability. Exploitation requires no authentication or user interaction and can be performed remotely over the network by sending specially crafted RTP packets to the vulnerable SFU. The fix, introduced in version 0.1.39, adds validation checks ensuring padLen is within valid bounds and returns an error instead of panicking. If upgrading is not feasible, users are advised to manually patch the code or drop packets with invalid padding indicators. Currently, there are no known exploits in the wild, but the ease of exploitation and the critical role of SFUs in real-time communications make this a significant threat to affected deployments.

For European organizations relying on real-time communication platforms that utilize Pion Interceptor, this vulnerability poses a substantial risk to service availability. SFUs are critical components in video conferencing, telepresence, and other RTP-based media streaming services. A successful attack could cause denial of service, disrupting business communications, remote collaboration, and customer-facing services. This is particularly impactful for sectors such as finance, healthcare, government, and education, where uninterrupted communication is essential. Additionally, organizations providing unified communications as a service (UCaaS) or hosted conferencing platforms may face reputational damage and financial losses due to service outages. Given the remote exploitability and lack of required authentication, attackers could launch denial-of-service attacks from outside the network, potentially amplifying the impact. The vulnerability does not expose sensitive data but can degrade operational continuity and user experience significantly.

European organizations should prioritize upgrading all instances of pion/interceptor to version 0.1.39 or later to ensure the vulnerability is fully patched. Where immediate upgrade is not possible, applying the patch from the relevant pull request manually is critical. Network-level mitigations include implementing RTP packet inspection and filtering to drop packets with the P-bit set but with invalid padding lengths (padLen zero or exceeding payload length). Deploying rate limiting and anomaly detection on RTP streams can help identify and mitigate suspicious traffic patterns that may indicate exploitation attempts. Organizations should also review their SFU deployment architectures to ensure redundancy and failover capabilities minimize downtime in case of attacks. Monitoring logs for panic events or crashes related to RTP packet processing can provide early warning signs. Finally, incorporating this vulnerability into incident response playbooks and conducting tabletop exercises will prepare teams to respond effectively to potential denial-of-service incidents.