A PoC was just published for a potentially serious flaw in the Ghostscript interpreter. Ghostscript can load Postscript, PDF, and SVG, and it has a feature from Postscript that has been a continual security issue: the
%pipe% command. This command requests the interpreter to spawn a new process — It’s RCE as part of the spec. This is obviously a problem for untrusted images and documents, and Ghostscript has fixed security vulnerabilities around this mis-feature several times over the years.
This particular vulnerability was discovered by [Emil Lerner], and described at ZeroNights X. That talk is available, but in Russian. The issue seems to be a bypass of sorts, where the pipe command appears to be working in the
/tmp/ directory, but a simple semicolon allows for an arbitrary command to be executed. Now why is this a big deal? Because ImageMagick uses Ghostscript to open SVG images by default on some distributions, and ImageMagick is often used for automatically resizing and converting images for web sites. In [Emil]’s presentation, he uses this flaw as part of an attack chain against three different companies.
I was unable to reproduce the flaw on my Fedora install, but I haven’t found any notice of it being fixed in the Ghostscript or Imagemagick changelogs either. It’s unclear if this problem has already been fixed, or if this is a true 0-day for some platforms. Either way, expect attackers to start trying to make use of it.
Continue reading “This Week In Security: Ghoscript In Imagemagick, Solarwinds, And DHCP Shenanigans”
You may have been one of the many of us who received an email from Ubiquiti this week, recommending a password change. The email stated that there was an unauthorized access of Ubiquiti systems, and while there wasn’t evidence of user data being accessed, there was also not enough evidence to say emphatically that user data was not accessed. Ubiquiti has mentioned that the database that may have been accessed contains a user’s name, email address, hashed password, and optionally the mailing address and phone number.
Depending on how the Ubiquiti authentication system is designed, that hashed password may be enough to log in to someone’s account. In any case, updating your password would invalidate the potentially compromised hash. This event underscores a complaint voiced by Ubiquiti users: Ubiquiti has been making it difficult to administrate hardware without a cloud-enabled account. Continue reading “This Week In Security: Ubiquiti, Nissan, Zyxel, And Dovecot”
Merry Christmas and happy holidays! I took Christmas day off from writing the security roundup, coming in a day early with this week’s installment, dodging New year’s day. The SolarWinds story has continued to dominate the news, so lets dive into it a bit deeper.
Microsoft has published their analysis of Solorigate, and the details are interesting. The added code was carefully written to blend in with the rest of the code, using the name
OrionImprovementBusinessLayer.Initialize, which sounds like a perfectly boring-yet-legitimate function. The actual backdoor is obfuscated using zip compression and base64 encoding.
Once this bootstrap code begins, it runs a series of checks before actually doing anything malicious. It waits 2 weeks after installation to do anything, and then checks the system domain name for any indication it’s running in a test environment. It then checks for certain security applications, like Wireshark, and refuses to run if they are detected. This series of checks all seem to be an effort to avoid detection, and to only run in a deployed environment. Even the Command and Control URL that the backdoor uses is constructed to appear benign. Beyond this, it seems that the malware simply waited for instructions, and didn’t take any automated actions. All the attacks were performed manually.
Continue reading “This Week In Security: Deeper Dive Into SolarWinds, Bouncy Castle, And Docker Images”
The big story this week is Solarwinds. This IT management company supplies network monitoring and other security equipment, and it seems that malicious code was included in a product update as early as last spring. Their equipment is present in a multitude of high-profile networks, like Fireeye, many branches of the US government, and pretty much any other large company you can think of. To say that this supply chain attack is a big deal is an understatement. The blame has initially been placed on APT42, AKA, the Russian hacking pros.
The attack hasn’t been without some positive effects, as Fireeye has released some of their internal tooling as open source as a result. Microsoft has led the official response to the attack, managing to win control of the C&C domain in court, and black-holing it.
The last wrinkle to this story is the interesting timing of the sale of some Solarwinds stock by a pair of investment firms. If those firms were aware of the breech, and sold their shares before the news was made public, this would be a classic case of illegal insider trading. Continue reading “This Week In Security: SolarWinds And FireEye, WordPress DDoS, And Enhance!”