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
- Oct 19, 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
modules/exploits/linux/local/netfilter_xtables_heap_oob_write_priv_esc.rb
Metasploit Framework modulesDeclared conditions
- platform: Linux($.exploit_linux/local/netfilter_xtables_heap_oob_write_priv_esc.platform)
- verification: check_declared($.exploit_linux/local/netfilter_xtables_heap_oob_write_priv_esc.check)
- kernel-exploitsExploit
Various kernel exploits
Responsible use
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