Up first this week is a warning for the few of us still brave enough to host our own email servers. If you’re running Zimbra, it’s time to update, because CVE-2024-45519 is now being exploited in the wild.
That vulnerability is a pretty nasty one, though thankfully requires a specific change from default settings to be exposed. The problem is in postjournal. This logging option is off by default, but when it’s turned on, it logs incoming emails. One of the fields on an incoming SMTP mail object is the RCPT TO: field, with the recipients made of the to, cc, and bcc fields. When postjournal logs this field, it does so by passing it as a bash argument. That execution wasn’t properly sanitized, and wasn’t using a safe call like execvp(). So, it was possible to inject commands using the $() construction.
The details of the attack are known, and researchers are seeing early exploratory attempts to exploit this vulnerability. At least one of these campaigns is attempting to install webshells, so at least some of those attempts have teeth. The attack seems to be less reliable when coming from outside of the trusted network, which is nice, but not something to rely on.
New Tool Corner
What is that binary doing on your system? Even if you don’t do any security research, that’s a question you may ask yourself from time to time. A potential answer is WhoYouCalling. The wrinkle here is that WYC uses the Windows Event Tracing mechanism to collect the network traffic strictly from the application in question. So it’s a Windows only application for now. What you get is a packet capture from a specific executable and all of its children processes, with automated DNS capture to go along. Continue reading “This Week In Security: Zimbra, DNS Poisoning, And Perfctl”
