Recent content on Staaldraad
Using a honeypot/honeyservice/honeytoken is one of the simplest and most impactful security actions one can take. Thinkst Canary has proven this over a number of years and continues to lead the field. Taking inspiration from what Thinkst has done and combining this with their idea of “honey tokens” for cloud services, I wrote metatrapd a couple of years back. Finally I’m making…
CVEs CVE-2017-11774 - Microsoft Outlook: Remote Code Execution CVE-2017-17405 - Ruby FTP: Remote Code Execution CVE-2018-11235 - Git: Remote Code Execution CVE-2018-16873 - Golang (go get): Remote Code Execution CVE-2019-0561 - Microsoft Word: Information disclosure CVE-2019-13139 - Docker: Command Injection to Remote Code Execution CVE-2020-25695 - Postgresql: restricted sandbox escape and…
CVEs CVE-2017-11774 - Microsoft Outlook: Remote Code Execution CVE-2017-17405 - Ruby FTP: Remote Code Execution CVE-2018-11235 - Git: Remote Code Execution CVE-2018-16873 - Golang (go get): Remote Code Execution CVE-2019-0561 - Microsoft Word: Information disclosure CVE-2019-13139 - Docker: Command Injection to Remote Code Execution CVE-2020-25695 - Postgresql: restricted sandbox escape and…
A really quick post about how we as security and engineering communicate. The language we use in communicating security issues has been spoken about often and we have gotten a lot better at making the language more inclusive and accessible. We still have a long way to go, but a shift away from confrontational language (we aren’t fighting a war) has, in my experience lead to better acceptance of…
It has taken me a long time to get around to writing this post, mostly because having an opinion about threat modeling can be so polarising. I’m expecting to be told “you are wrong!”, “that is not what threat modeling is!”, and “that is not how you threat model!”. Fortunately, this is the internet, and we all get to have our own wrong opinions. What follows are…
A couple of years ago I wrote a universal YAML.load deserialization RCE gadget based on the work by Luke Jahnke from elttam. This has since been patched and no longer works on Ruby versions after 2.7.2 and Rails 6.1. Fortunately, William Bowling (vakzz) has found a new gadget chain that works on all Ruby versions 2.x - 3.x. His write-up for this is excellent and I highly recommend you give it a…
Este año está siendo una locura, espero que todos estéis bien y que el resto del año vaya mejor. Este es mi primer y probablemente único post del año (y el primero en español). Voy a hablar sobre una vulnerabilidad que hallé en Postgresql, y que afecta a todas las versiones desde la 9.5, y probablemente también, las versiones anteriores. La vulnerabilidad es similar a una “time-of-check to…
It has been quite a year, I hope everyone is well and staying safe. This is my first and probably only post for the year, and covers a fun privilege escalation vulnerability I found in Postgresql. This affects all supported versions of Postgresql going back to 9.5, it is likely it affects most earlier versions as well. The vulnerability is similar to a time-of-check to time-of-use (TOCTOU) issue,…
This is going to be a short write-up about an interesting argument injection I ran into a while ago. There is nothing new here, but it is still worth looking at as argument injection is an oft overlooked attack avenue as everyone is going after the more traditional command injection vulnerabilities. What is argument injection? Very similar to command injection, argument injection occurs when…
Earlier in the year, while doing some research for my talk at Troopers 2019, in which I examined build systems and the how git can cause security issues, I found a git related vulnerability in Docker. This vulnerability has since been assigned CVE-2019-13139 and was patched in the Docker engine update 18.09.4. The issue is a relative straight forward command injection, however, what possibly makes…
Containers, Docker containers in particular, are deployed everywhere these days. This is especially true in build environments or your typical CI/CD pipeline. A frequent requirement in these environments is the ability to build Docker container images, which tends to introduce security vulnerabilities through misconfiguration. One typically finds that the docker daemon is exposed to allow for…
Last year I stumbled across a vulnerability in Go’s go get command, which could lead to code execution when a malicious Go package was downloaded. I reported this to the Go team and it was subsequently assigned CVE-2018-16873 . The actual vulnerability was really interesting since it was solely a logic vulnerability, where I abused the order in which packages were cloned by the go get…
Last year Luke Jahnke wrote an excellent blog post on the elttam blog about finding a universal RCE deserialization gadget chain for Ruby 2.x. In the post he discusses the process of finding and eventually exploiting a gadget chain for Marshal.load . I was curious if the same chain could be used with YAML.load . It has been shown before that using YAML.load with user supplied data is bad, but all…
It has been a while since the Git vulnerability was announced. The major public repository providers have long since been preventing hosting repositories serving CVE-2018-11235.
Shortly after the recent Git vulnerability was announced, a security advisory for Kubernetes was published.
Remote code execution through malicious submodules.
The FTP library in Ruby did not validate remote filenames and blindly passed these to the kernel.open function. This created a remotely exploitable vulnerability. Since the filenames were supplied by the remote FTP server, it was possible to create a malicious server that could exploit this vulnerability when a vulnerable Ruby client connected and tried to download a file.
GraphQL provides a powerful query language for APIs and we can abuse some built in features to map out the attack surface.
Before creating this blog, I had the opportunity to create numerous posts under the SensePost blog . These cover a few topics including mobile apps, web apps and infrastructure.
Recently I was doing an assessment in a locked down and restricted environment. One of the first actions you tend to do when landing a shell on a [linux] box is to do some reconnaissance. This is both on host and network, as you want to determine what new access this host has given you. Normally you would run netstat, ifconfig, ip route etc to determine if the compromised host is connected to any…
When doing external assessments you spend a decent amount of time footprinting your target and finding possible avenues of attack. Given a large corporate, you are pretty likely to hit video conferencing end-points. This post details a vulnerability in one of these video conferencing systems, the Polycom HDX series. I identified this vulnerability while still at SensePost and reported it to…
A few weeks back Saif El-Sherei and I posted on the SensePost blog about DDE and getting command exec in MSWord without macros. This post got way more attention than we initially expected it would. Since then DDE has been used in phishing and malware campaigns, as well as legitimate red-team engagements. With the rapid rise in attacks using DDE, detection has been stepped up and most AV engines…
Typically phishing has provided a low tech approach to getting access to credentials and services. The mainfocus up until now has been on getting username&passwords or tricking users into executing code. Subsequently, user awareness has gone up and users are better at identifying suspicious pages. Experience has shown that the click-through rate on emails have remained high, while users have been…
A recent research project/idea required me to look into setting up a NAT-to-NAT VPN. The basic idea being that two NATed networks are able to communicate through a VPN and share resources. While researching possible VPN solutions, I remembered reading about WireGuard a new VPN that aims to be fast, secure and lightweight. This seemed like the perfect opportunity to both try out a new VPN…
XXE - FTP OoB basics XXE offers a great attack avenue for reading files from a vulnerable web-app. One of my favourite XXE attacks involves protocol handler abuse, where you use FTP to do an out of band read. This is useful in those cases where you have XXE but it is blind. Unlike the normal OoB retreival through HTTP, FTP works with newer versions of Java (>1.7) and there are fewer characters…
On numerous occasions I’ve run into custom binary network protocols that I’ve wanted to reverse. The usual goto here is to fireup wireshark/tcpdump and view the traffic as it goes accross the wire. This works really well in most cases, but how about traffic that uses TLS to encrypt the traffic? Unless you have the private key for the server, you are stuck with viewing encrypted traffic…
It’s been a while… I figured it’s about time I post something here again. A while back I was required to see how much damage can be done by a malicious staff member. The one caveat here was that I had to test directly from the Windows box and had extremely limited outbound comms. For various reasons the usual tool-suites were out and I took this as a challenge to see how much…
A few assessments back I ran into a web app that made libral use of websockets. Now it’s been a while since encountering an app that makes use of websockets for such a large portion of it’s content and I’d forgotten what a PITA it can be trying to intercept and replay websocket requests. Seeing as it was a web app assessment I naturally turned to trusty Burp Suite Pro. Burp has…
Every now and then you run into a new file format and you find that you may not have a tool to parse that file. Or you are looking for an easy to use solution for you mom to access the photo’s you sent her in a .tar archive. This is where file conversion services come in, a quick Google for “online file converter” will yield multiple results. One thing to keep in mind when…
In the past our favourite hardware vendor to pick on was Cisco these days however, there is a new kid on the block - Huawei. We all know about the dangers of SNMP and default community strings, think Cisco and tftp. Seems like Huawei suffers from similar fail. Like all routers, switches, servers, ect out there, Huawei devices can be managed through SNMP. And just like other devices in the wild,…
Mongo provides a native shell for interacting with local and remote MongoDB instances. In rare cases you may find that a user’s logon shell has been replaced with this Mongo shell, this could happen when there is a shared machine where you want developers/admins to access the database but not have native access to the host. Everytime the user logs in, they hit the mongo shell, can execute…
A while back I spent some time playing with the “modern” database implementations, more affectionately known as hipster tech. These are mostly your so-called NoSQL, big-data, ect databases. Trying to interact with these databases required numerous scripts to be written, one for each database implementation. After chatting to @PaulWebSec I decided to merge these into a single tool. Thus HippyDB…