Skip to main content

Tags denial of service

A Novel DoS Vulnerability affecting WebRTC Media Servers

Published on Jun 25, 2024 in , , ,

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.…

Read more »

OpenSIPS Security Audit Report is fully disclosed and out there

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.…

Read more »

Exploiting CVE-2022-0778, a bug in OpenSSL vis-à-vis WebRTC platforms

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.…

Read more »

Killing bugs … one vulnerability report at a time

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?…

Read more »

One presentation at ClueCon and five security advisories for FreeSWITCH

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:…

Read more »

Why volumetric DDoS cripples VoIP providers and what we see during pentesting

Published on Oct 13, 2021 in ,

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.…

Read more »

Massive DDoS attacks on VoIP Providers and simulated DDoS testing

Published on Sep 24, 2021 in ,

VoIP.ms and other VoIP providers under DDoS attack At the time of writing, a major VoIP provider called VoIP.ms is under a distributed denial of service (DDoS) attack since over a week. As a result, they are unable to serve their customers with everyone and their dog complaining that they cannot connect to VoIP.ms’s SIP servers as well as other resources. At the same time, someone claiming to be part of the REvil ransomware group is blackmailing the provider.…

Read more »

DEMO - An overview of the VoIP and RTC offensive security toolset, SIPVicious PRO

We pushed out a video that introduces the basics of SIPVicious PRO by demonstrating some of the attack tools and showing the building blocks for automating security testing of VoIP and WebRTC applications and infrastructure. What follows is a transcript of the video. Introduction Hello, I’m Sandro Gauci from Enable Security. In this video, I’d like to show you what we have been working on, SIPVicious PRO! Let’s start by introducing the tools.…

Read more »

TADSummit Asia 2021 talk about SIPVicious Pro and the Demo Server

TADSummit is a great event where people from different backgrounds that are somehow involved in communications, contribute in various ways. I, personally, always look forward to see what’s coming up in the next TADSummit event. At the moment, TADSummit Asia presentations are currently being released on a daily basis on the main site. And last week, the presentation that I prepared was published! In the previous TADSummit, I had presented about why we need to bring an offensive approach to RTC security.…

Read more »