CVE-2024-49940

A flaw was found in the Linux kernel's implementation of the Layer 2 Tunneling Protocol (L2TP). A race condition during the creation and registration of L2TP sessions can lead to a tunnel reference count underflow. This issue allows a local attacker with low privileges to cause a Denial of Service (DoS) by making the system unstable or unresponsive.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the l2tp_core kernel module from loading. This can be achieved by blacklisting the module. To temporarily unload the module (if not in use): # modprobe -r l2tp_core To permanently blacklist the module, create a configuration file: # echo "blacklist l2tp_core" >> /etc/modprobe.d/blacklist-l2tp.conf A system reboot or module reload is required for the change to take full effect. Disabling this module may impact L2TP VPN functionality.