CVE-2021-22600 vulnerability in Canonical and Other Products
Published on January 26, 2022
Double Free in net/packet/af_packet.c leading to priviledge escalation
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, requires user interaction and a small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. This vulnerability is known to be actively exploited by threat actors. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
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
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Affected Versions
Linux Kernel Kernel:- Version unspecified and below 5.4.168 is affected.
- Version unspecified and below 5.10.88 is affected.
- Version unspecified and below 5.15.11 is affected.
- Version unspecified and below 5.16-rc6 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.