Netfilter is a framework in the Linux kernel for implementing various networking-related tasks with user-defined handlers. Netfilter provides various functions for packet filtering, network address translation and port translation, and packet logging. Netfilter represents a set of hooks that allow other kernel modules to register callback functions in the kernel’s networking stack.

Open-source code runs on every computer on the planet—and keeps America’s critical infrastructure going. DARPA is worried about how well it can be trusted

At Grapl we believe that in order to build the best defensive system we need to deeply understand attacker behaviors. As part of that goal we're investing in offensive security research. Keep up with our blog for new research on high risk vulnerabilities, exploitation, and advanced threat tactics.

Diverto is an information security company. We provide consulting and managed services.

A few weeks ago, I found and reported CVE-2022-25636 - a heap out of bounds write in the Linux kernel. The bug is exploitable to achieve kernel code execution (via ROP), giving full local privilege escalation, container escape, whatever you want.

This is the story of CVE-2022-0847, a vulnerability in the Linux kernel since 5.8 which allows overwriting data in arbitrary read-only files. This leads to privilege escalation because unprivileged processes can inject code into root processes. It is similar to CVE-2016-5195 “Dirty Cow” but is easier to exploit. The vulnerability was fixed in Linux 5.16.11, 5.15.25 and 5.10.102.

Netfilter is a framework in the Linux kernel for implementing various networking-related tasks with user-defined handlers. Netfilter provides various functions for packet filtering, network address translation and port translation, and packet logging. Netfilter represents a set of hooks that allow other kernel modules to register callback functions in the kernel’s networking stack.

Open-source code runs on every computer on the planet—and keeps America’s critical infrastructure going. DARPA is worried about how well it can be trusted

At Grapl we believe that in order to build the best defensive system we need to deeply understand attacker behaviors. As part of that goal we're investing in offensive security research. Keep up with our blog for new research on high risk vulnerabilities, exploitation, and advanced threat tactics.

Diverto is an information security company. We provide consulting and managed services.

A few weeks ago, I found and reported CVE-2022-25636 - a heap out of bounds write in the Linux kernel. The bug is exploitable to achieve kernel code execution (via ROP), giving full local privilege escalation, container escape, whatever you want.

This is the story of CVE-2022-0847, a vulnerability in the Linux kernel since 5.8 which allows overwriting data in arbitrary read-only files. This leads to privilege escalation because unprivileged processes can inject code into root processes. It is similar to CVE-2016-5195 “Dirty Cow” but is easier to exploit. The vulnerability was fixed in Linux 5.16.11, 5.15.25 and 5.10.102.