canonical ubuntu-linux CVE-2021-22600 vulnerability in Canonical and Other Products
Published on January 26, 2022

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A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755

NVD

Known Exploited Vulnerability

This Linux Kernel Privilege Escalation Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Linux Kernel contains a flaw in the packet socket (AF_PACKET) implementation which could lead to incorrectly freeing memory. A local user could exploit this for denial-of-service or possibly for privilege escalation.

The following remediation steps are recommended / required by May 2, 2022: Apply updates per vendor instructions.

Vulnerability Analysis

CVE-2021-22600 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. It has an exploitability score of 1.0 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

What is a Double-free Vulnerability?

The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. When a program calls free() twice with the same argument, the program's memory management data structures become corrupted. This corruption can cause the program to crash or, in some circumstances, cause two later calls to malloc() to return the same pointer. If malloc() returns the same value twice and the program later gives the attacker control over the data that is written into this doubly-allocated memory, the program becomes vulnerable to a buffer overflow attack.

CVE-2021-22600 has been classified to as a Double-free vulnerability or weakness.


Products Associated with CVE-2021-22600

You can be notified by stack.watch whenever vulnerabilities like CVE-2021-22600 are published in these products:

Canonical Ubuntu Linux
 
Linux Kernel
 
Debian Linux
 

What versions are vulnerable to CVE-2021-22600?

Each of the following must match for the vulnerability to exist.

Each of the following must match for the vulnerability to exist.

Each of the following must match for the vulnerability to exist.

Each of the following must match for the vulnerability to exist.

Each of the following must match for the vulnerability to exist.