Critical Use-After-Free Vulnerability in Linux Kernel STP Disclosed

A use-after-free vulnerability has been identified in the Linux kernel's bridge implementation affecting the Spanning Tree Protocol (STP). This flaw allows for timer structures to reference freed memory, potentially enabling control-flow hijacking. The vulnerability arises when a bridge is administratively down while STP is enabled, leading to a situation where timers are not properly deleted. A proof-of-concept (PoC) has been released, increasing the risk of exploitation. The issue affects systems using the Linux kernel's network bridge functionality. Security teams are urged to assess their environments for potential exposure. The vulnerability has not been assigned a CVE number yet, but it is considered critical due to the PoC availability.

Key Points: • A critical use-after-free vulnerability in Linux kernel's STP implementation has been disclosed. • A proof-of-concept (PoC) is available, increasing the risk of exploitation. • The flaw affects systems using the Linux kernel's network bridge functionality.