Tags › denial of service
Sandro talks RTC Security with Safety Detectives
Published on Aug 6, 2025 in voip security, sipvicious pro, denial of service
Our CEO discusses why generic security tools fail for voice protocols, how ESAP addresses RTC-specific vulnerabilities, and emerging AI threats in real-time communications.…
Rtpengine RTP Injection and Media Bleed Vulnerabilities (CVE-2025-53399)
Published on Jul 31, 2025 in voip security, research, rtpengine, denial of service, webrtc security, sip security
We published a critical security advisory for rtpengine affecting versions mr13.3.1.4 and lower, allowing RTP injection and media redirection attacks. These vulnerabilities can be exploited without man-in-the-middle positioning and affect both plaintext RTP and encrypted SRTP sessions. Organizations should upgrade to mr13.4.1.1 and review configuration settings.…
New White Paper: DTLS “ClientHello” Race Conditions in WebRTC Implementations
Published on Oct 15, 2024 in denial of service, freeswitch, webrtc security, asterisk
We’re excited to announce the release of our latest white paper, “DTLS ‘ClientHello’ Race Conditions in WebRTC Implementations”. This comprehensive study delves into a critical vulnerability affecting various WebRTC implementations, with potential implications for real-time communication security. Our research team at Enable Security conducted extensive testing on both open-source and proprietary WebRTC implementations, focusing on media servers and popular communication platforms. The study aimed to identify vulnerabilities related to the processing of DTLS ClientHello messages in WebRTC sessions.…
A Novel DoS Vulnerability affecting WebRTC Media Servers
Published on Jun 25, 2024 in denial of service, freeswitch, webrtc security, asterisk
Executive summary (TL;DR) A critical denial-of-service (DoS) vulnerability has been identified in media servers that process WebRTC’s DTLS-SRTP, specifically in their handling of ClientHello messages. This vulnerability arises from a race condition between ICE and DTLS traffic and can be exploited to disrupt media sessions, compromising the availability of real-time communication services. Mitigations include filtering packets based on ICE-validated IP and port combinations. The article also indicates safe testing methods and strategies for detecting the attack.…
OpenSIPS Security Audit Report is fully disclosed and out there
Published on Mar 17, 2023 in sip security, sipvicious pro, sip security testing, security tools, opensips, kamailio, fuzzing, denial of service, research
It’s almost a year since the OpenSIPS project published a minimized version of our security audit report from 2022. Now, the full version has been published, with all the information intact on how to reproduce the vulnerabilities and extra details in an 80+ page report. The OpenSIPS security audit report can be found here. What is the OpenSIPS security audit? OpenSIPS is a SIP server that often has a critical security function within an IP communications system.…
How to perform a DDoS attack simulation
Published on Nov 29, 2022 in denial of service, voip security
TL;DR A DDoS simulation is a practical exercise that various organisations are capable of doing. Understand the reasons why you would want to do this, then combine custom with off-the-shelf attack tools. Follow the best practices, apply solutions and mitigation; and you can finally answer: what if we got attacked? Introduction In this post, we give an overview of how you too can perform your own distributed denial of service (DDoS) simulation exercises.…
Exploiting CVE-2022-0778, a bug in OpenSSL vis-à-vis WebRTC platforms
Published on Apr 8, 2022 in denial of service, demo server, freeswitch, asterisk, webrtc security, kamailio, sipvicious pro
Executive summary (TL;DR) Exploiting CVE-2022-0778 in a WebRTC context requires that you get a few things right first. But once that is sorted, DoS (in RTC) is the new RCE! How I got social engineered into looking at CVE-2022-0778 A few days ago, Philipp Hancke, self-proclaimed purveyor of the dark side of WebRTC, messaged me privately with a very simple question: “are you offering a DTLS scanner by chance?” He explained how in the context of WebRTC it would be a bit difficult since you need to get signaling right, ICE (that dance with STUN and other funny things) and finally, you get to do your DTLS scans.…
Killing bugs … one vulnerability report at a time
Published on Oct 29, 2021 in freeswitch, voip security, conferences, denial of service, sipvicious pro
Executive summary (TL;DR) We tell the story behind the latest FreeSWITCH advisories and how it all came together one sleepless night in April 2021 so that we ended up with 4 vulnerabilities that needed reporting. And then, one more vulnerability found due to a bug in our own software, SIPVicious PRO. We explain how these flaws were discovered, reported, fixed and what we ultimately learned through this process. What is this about?…
One presentation at ClueCon and five security advisories for FreeSWITCH
Published on Oct 25, 2021 in freeswitch, voip security, conferences, denial of service, sipvicious pro
The FreeSWITCH team has just published version v1.10.7 which fixes a number of security issues that we reported. If you use FreeSWITCH, please do upgrade to get these security updates. To learn about the background work that went into getting these security bugs squashed, follow Sandro’s talk called Killing bugs … one vulnerability report at a time. This will be presented at at ClueCon on Thursday, October 28th. Here are the titles of each advisory and a very short summary:…
Why volumetric DDoS cripples VoIP providers and what we see during pentesting
Published on Oct 13, 2021 in denial of service, voip security
An epiphany Until a few days ago, I was of the opinion that simulating volumetric DDoS attacks is not something we should be doing. If you had asked us for such a test, we would have given you a negative answer. Ironically, we had been unwittingly simulating volumetric DDoS attacks while quietly ignoring our own results. But, it’s time to stop neglecting bandwidth saturation and start giving it the attention that it deserves.…