Tags › Sipvicious Pro

Bug discovery diaries: Abusing VoIPmonitor for Remote Code Execution

Executive summary (TL;DR)

We fuzzed VoIPmonitor by using SIPVicious PRO and got a crash in the software’s live sniffer feature when it is switched on. We identified the cause of the crash by looking at the source code, which was a classic buffer overflow. Then we realized that was fully exploitable since the binaries distributed do not have any memory corruption protection. So we wrote exploit code using ROP gadgets to get remote code execution by just sending a SIP packet. We also reported this upstream so that it was fixed in the official distribution.

SIPVicious PRO 6.0.0-beta.2 takes STDIN and fixes various bugs

What we’re excited about in this minor update is the addition of a new feature to the SIP cracker in SIPVicious PRO. Basically, it now takes input from external tools through standard input.

Why? Because it allows infinite ways of generating potential usernames, passwords and/or SIP extensions when making use of external tools such as the maskprocessor included in the well known password cracker, hashcat. Here’s an animation showing usage of the maskprocessor to generate passwords for the SIP online cracking tool:

Bug discovery diaries: uncovering sngrep overflow issues with blackbox fuzzing

Executive summary (TL;DR)

During OpenSIPIt, we crashed sngrep by mistake while briefly fuzzing OpenSIPS. Later on we setup a docker environment to reproduce the issue, identified the actual bugs and reported them upstream. If you want to learn the simple steps to do this, you actually have to read the rest of the post :-)

sngrep crash during the live OpenSIPit event

Last year we participated in OpenSIPIt’s interoperability testing event which was held between the 14th and 15th of September 2020. Amongst the topics discussed were RFC8760 (SHA-digest), STIR/SHAKEN and RFC8599 (push notifications). Whilst trying to stick to the agenda, we couldn’t resist the temptation to fuzz test the servers that were available to us. An instance of OpenSIPS was tested for a very short period of time, however, we did not observe any server crashes.

SIPVicious PRO beta release contains SIP fuzzer and better automation

We just made SIPVicious PRO v6.0.0-beta.1 available to our beta testers. This latest release brings a new SIP fuzzer and enhancements for automation to your favourite RTC offensive security toolset. We have the following highlights with this release:

• New fuzzing tools - sip fuzz method. This used to be in a separate internal tool called gasoline (see our toolset page); this now been polished and has joined the SVPRO toolset; this has been used to identify vulnerabilities in Kamailio (advisory), sngrep (advisory 1 and 2) and other SIP servers.
• Tool results provided at the end of a test are now standardized with a JSON schema so that they can easily be parsed or used to produce reports by third-party tools. See the documentation about automation and results.
• Exit codes updated for future compatibility when using it within automation systems. See the documentation about signal handling and exit codes.
• Full IPv6 support across all tools.
• Documentation site is now refreshed, and central to SIPVicious PRO at https://docs.sipvicious.pro.
• And of course, various bug fixes. Full changelog can be seen here.

How doing QA testing for SIPVicious PRO led to an Asterisk DoS

Executive summary (TL;DR)

While heavily testing SIPVicious PRO for bugs, we encountered an unexpected crash in Asterisk. We reported this to the Asterisk team, who recently issued a fix. If you’re a vendor, you too can beta test SIPVicious PRO!

How the Asterisk crash was found

We test our software as much as we can because, like any other software, ours contains bugs too! When it comes to SIPVicious PRO, one of our quality assurance tests is to run it against instances of Asterisk and Kamailio and check for expected results. Our test suite loads these servers in a docker environment and automatically runs SIPVicious PRO against these targets. During these tests, we look for crashes, race conditions and other unchecked states that we might have failed to address in our own code. We do this through various methods, one of which is to observe exit codes in SIPVicious PRO that indicate the result of the test.

SIPVicious PRO v6.0.0 alpha.5 available to our clients

With great pleasure, we announce the availability of the v6.0.0-alpha.5 version of SIPVicious PRO. This is a major update since most of the promised feature-set of the existent modules is now available. While you are encouraged to read the release notes, the main highlights are the following:

• Target demo server (demo.sipvicious.pro) now implemented, used throughout the documentation for attack examples and training purposes
• An extensive getting started page is now available, with instructions on how to use most of the modules
• Exit codes! Yes, for automation, say, in your CI pipelines
• All flags that were previously marked as TODO are now fully functional (with the exception of DTLS SRTP)
• SDES SRTP supported throughout all modules
• DTMF tone generation, because in RTP inject attacks, this is particularly useful
• Lots of bug fixes and refactoring thanks to more consistent internal testing and the perseverance of our dear developers and internal testers

If you already have access to SVPRO, then you should have received an email from us with further details. If not, and if you work for a vendor, service provider or develop an opensource VoIP or WebRTC project, please see our instructions on how to get SIPVicious PRO.

What’s up with SIPVicious PRO?

In the past 3 years we have been working on developing SIPVicious PRO during our work as penetration testers and in between engagements. Since our chief demolition officer, Alfred joined up with Enable Security, the development has had a much-needed push so that we started making it available to a limited number of companies that happen to be our clients.

Today, we’re making version 6.0.0-alpha.4 available to our clients which includes Opus support, further support for SRTP and of course, a number of bug fixes. Our release notes can be read at the support site.