A new vulnerability that affects many Linux systems has been revealed: Pwnkit. This attack uses a vulnerability in polkitd to allow any user to escalate his privileges to root. There are patches for major Linux systems: see the LowEndTalk thread. Thanks to @FoxelVox for posting this on LET.
It’s important to note that the vulnerability can only be used by users logged into the system. You can’t launch this attack on just any Linux box you ping on the network.
I tested on my Debian 11 systems. I find that none of my remote VMs are running polkitd, which is a user privilege management tool (previously called PolicyKit), however all of my home systems are. On my VMs, without polkitd running, the attack compiles but doesn’t work. However, it works just fine where polkitd is running.
Patch your systems ASAP!
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raindog308 is a longtime community LETizen, technical writer, and self-described techno polymath. With deep roots in the *nix world, he has a passion for systems both modern and vintage, ranging from Unix, Perl, Python, and Golang to shell scripting and mainframe-era operating systems like MVS. He’s equally comfortable with relational database systems, having spent years working with Oracle, PostgreSQL, and MySQL.
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Dear Dreadlord. Is this still a problem if I (to my knowledge) only have one user (root) i.e. me?! Web requests come in from the www-data user, though. Thank you. Jon.C.
No they must have a shell…unless they can trick your php app into executing something on the server…