Exploitation involves sending a malicious UDP packet to port 631 on the target, directing it to an attacker-controlled IPP server.
Okay, so at least until this is patched, it would be a good idea to shut down any process that’s listening on port 631, and avoid interaction with untrusted or potentially compromised print servers.
Either of these commands will list any such processes:
That refers to the fact that printer advertisements can contain lies: Although you might see a familiar printer name appear on a network, it might secretly point to the address of a malicious device.
So my first advice stands: Avoid interaction with untrusted or potentially compromised print servers.
To be clear, when I say “interaction”, I don’t just mean printing to them. I mean any interaction at all. Even just browsing a network for printers could potentially mean your system contacts the devices at the advertised addresses, and receives data from them. This Qualys report doesn’t make clear whether this kind of interaction is safe, so I have to assume for now that it is not.
mox@lemmy.sdf.org 8 months ago
Okay, so at least until this is patched, it would be a good idea to shut down any process that’s listening on port 631, and avoid interaction with untrusted or potentially compromised print servers.
Either of these commands will list any such processes:
$ sudo lsof -i :631$ sudo fuser -v 631/tcp 631/udpToes@ani.social 8 months ago
What are your thoughts on the alternative path the article talks about “…zeroconf, mDNS, or DNS-SD advertisements”?
mox@lemmy.sdf.org 8 months ago
That refers to the fact that printer advertisements can contain lies: Although you might see a familiar printer name appear on a network, it might secretly point to the address of a malicious device.
So my first advice stands: Avoid interaction with untrusted or potentially compromised print servers.
To be clear, when I say “interaction”, I don’t just mean printing to them. I mean any interaction at all. Even just browsing a network for printers could potentially mean your system contacts the devices at the advertised addresses, and receives data from them. This Qualys report doesn’t make clear whether this kind of interaction is safe, so I have to assume for now that it is not.