CVE-2021-22555
Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE
- Published
- Jul 7, 2021
- Updated
- Dec 30, 2025
- Assigning CNA
- Evidence observed
- Jul 15, 2021
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HHigh · next 30 days
- Percentile
- 99.6%
- Model date
- Sep 21, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
CISA Known Exploited
This CVE appears in the CISA Known Exploited Vulnerabilities catalog.
Summary
A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space
Sources
16- kernel-exploitsExploit
Various kernel exploits
Containerized reproducer for CVE-2021-22555 Linux privilege escalation, with seccomp mitigation profiles and deployment guidance for Kubernetes and OpenShift clusters.
- CVE-2021-22555Exploit
This repo hosts TUKRU's Linux Privilege Escalation exploit (CVE-2021-22555). It demonstrates gaining root privileges via a vulnerability. Tested on Ubuntu 5.8.0-48-generic and COS 5.4.89+. Use responsibly and ethically.
Responsible use
Use vulnerability information only on systems you own or are authorized to test. Kitploit links to public research metadata and does not store exploit code or malicious payloads.