Security Researchers Create Proof-of-Concept Program that Evades Linux Syscall-Watching Antivirus
Slashdot reader Mirnotoriety shared this report from the Register: A proof-of-concept program has been released to demonstrate a so-called monitoring "blind spot" in how some Linux antivirus and other endpoint protection tools use the kernel's io_uring interface. That interface allows applications to make IO requests without using traditional system calls [to enhance performance by enabling asynchronous I/O operations between user space and the Linux kernel through shared ring buffers]. That's a problem for security tools that rely on syscall monitoring to detect threats... [which] may miss changes that are instead going through the io_uring queues. To demonstrate this, security shop ARMO built a proof-of-concept named Curing that lives entirely through io_uring. Because it avoids system calls, the program apparently went undetected by tools including Falco, Tetragon, and Microsoft Defender in their default configurations. ARMO claimed this is a "major blind spot" in the Linux security stack... "Not many companies are using it but you don't need to be using it for an attacker to use it as enabled by default in most Linux systems, potentially tens of thousands of servers," ARMO's CEO Shauli Rozen told The Register. "If you're not using io_uring then disable it, but that's not always easy with cloud vendors." Read more of this story at Slashdot.
Slashdot reader Mirnotoriety shared this report from the Register:
A proof-of-concept program has been released to demonstrate a so-called monitoring "blind spot" in how some Linux antivirus and other endpoint protection tools use the kernel's io_uring interface.
That interface allows applications to make IO requests without using traditional system calls [to enhance performance by enabling asynchronous I/O operations between user space and the Linux kernel through shared ring buffers]. That's a problem for security tools that rely on syscall monitoring to detect threats... [which] may miss changes that are instead going through the io_uring queues.
To demonstrate this, security shop ARMO built a proof-of-concept named Curing that lives entirely through io_uring. Because it avoids system calls, the program apparently went undetected by tools including Falco, Tetragon, and Microsoft Defender in their default configurations. ARMO claimed this is a "major blind spot" in the Linux security stack... "Not many companies are using it but you don't need to be using it for an attacker to use it as enabled by default in most Linux systems, potentially tens of thousands of servers," ARMO's CEO Shauli Rozen told The Register. "If you're not using io_uring then disable it, but that's not always easy with cloud vendors."
Read more of this story at Slashdot.
