Linux is an operating system that has security in mind from its first days. Today Linux may be considered the most secure OS in the market, especially for the web hosting and cloud computing industries. In the last months, Linux had critical security patches. This time security researchers have discovered a heap overflow vulnerability in the Transparent Inter-Process Communication module of the kernel.
Included in all common Linux distributions
Exploiting this vulnerability lets the hackers execute arbitrary code within the kernel and completely compromise the system. The vulnerable TIPC module is included in all common Linux distributions. The good news, the user must load the module to activate the protocol. TIPC enables the nodes in a cluster to communicate efficiently while remaining fault-tolerant. The origin of the flaw is based on the user message type called MSG_CRYPTO which was introduced in September 2020.
The vulnerability was reported and thanks to the cooperation with the Linux Foundation and one of the TIPC managers, the patch was released on October 29th. The patched version has been available in current Linux versions (after 5.15) since October 31st. If you are a TIPC user, check whether your Linux kernel version is between 5.10-rc1 and 5.15. If not, we highly recommend you update it.
Linux security researchers at SentinelOne Labs talked about vulnerability,
“As for the data being overwritten, at first glance it may look like the overflow will have uncontrolled data, since the actual message size used to allocate the heap location is verified. However, a second look at the message validation function shows that it only checks that the message size in the header is within the bounds of the actual packet. That means that an attacker could create a 20-byte packet and set the message size to 10 bytes without failing the check.”