A new Linux Kernel vulnerability called “DirtyCred” was disclosed at the Black Hat security conference on August 10, 2022. The vulnerability, which is similar to the notorious DirtyPipe vulnerability and is tracked as CVE-2022-0847, was discovered by Ph.D. detected by student Zhenpeng Lin and his team.
DirtyCred is a kernel exploit that replaces non-privileged kernel credentials with privileged ones to escalate privileges on vulnerable systems. Instead of overwriting any critical data area in the kernel stack, DirtyCred abuses the stack memory reuse mechanism to gain privileges. It can overwrite all files with reading permission that affects kernel version 5.8 or higher. The vulnerability allows a local threat actor to crash the system or execute arbitrary code on the vulnerable system.
Security researchers have posted a demo on their social media accounts showing how the DirtyCred vulnerability can be used to elevate the privileges of a low-privileged user on two different systems, such as Centos 8 and Ubuntu, using the same Exploit code with the DirtyPipe vulnerability.
This Thursday @BlackHatEvents , I will be presenting our research on a kernel exploitation method named #DirtyCred. With DirtyCred, you could write an #DirtyPipe liked exploit that works on different kernels and ARCHs without code changes. Check it out https://t.co/Qip23PSHl7 pic.twitter.com/jdopannoBO
— Zhenpeng Lin (@Markak_) August 7, 2022
There are currently no mitigations or updates to the DirtyCred exploit. Security researchers recommend separating privileged credentials from non-privileged ones using virtual memory to prevent potential Cross-Cache attacks using the vulnerability.