A critical flaw in the Linux kernel’s IPv6 stack, identified as CVE-2023-6200, has been uncovered, which could permit attackers to execute arbitrary code. This high-severity issue, rated with a CVSS score of 7.5, poses a significant threat to network security.
Exploitable Through ICMPv6 Router Advertisements
The vulnerability could be exploited by an attacker on a local network through specially crafted ICMPv6 router advertisement packets. These packets are an integral part of the IPv6 protocol, employed for network configuration.
Red Hat’s Advisory on the Race Condition
Red Hat’s advisory highlights a race condition within the Linux Kernel that facilitates the attack. The issue arises when an unauthenticated attacker sends an ICMPv6 router advertisement packet under certain conditions, leading to unauthorized code execution.
Local Network Attack Vector and Default Configurations
The flaw primarily allows for local network attacks, as the risk is mitigated by default configurations in systems like Red Hat Enterprise Linux, where the vulnerable setting is disabled. This limits the potential for remote exploitation.
Steps for Mitigation and Verification
Mitigation involves ensuring the ‘accept_ra’ parameter is disabled, which can be verified through specific system commands. If the IPV6 protocol or the parameter is not enabled, the system is not susceptible to the vulnerability.
Resolution with Kernel Update
The issue has been resolved in the latest kernel update to version 6.7-rc7. Users are urged to update their systems to safeguard against potential attacks exploiting this vulnerability.
