CVE-2021-22555

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

Published: Jul 7, 2021
Updated: Nov 4, 2025
CVE: CVE-2021-22555
Severity: High
Exploit:

CVSS v3:

Severity: High
Score: 8.3
AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS v2:

Severity: Low
Score: 4.6
AV:L/AC:L/Au:N/C:P/I:P/A:P

CWEs:

CWE-787

Affected Software
References

Software	From	Fixed in
linux / linux_kernel	5.11	5.12
linux / linux_kernel	5.5	5.10.31
linux / linux_kernel	4.20	5.4.113
linux / linux_kernel	4.15	4.19.188
linux / linux_kernel	2.6.19	4.4.267
linux / linux_kernel	4.10	4.14.231
linux / linux_kernel	4.5	4.9.267
netapp / solidfire_baseboard_management_controller	-	-

http://packetstormsecurity.com/files/163528/Linux-Kernel-Netfilter-Heap-Out-Of-Bounds-Write.html
http://packetstormsecurity.com/files/163878/Kernel-Live-Patch-Security-Notice-LSN-0080-1.html
http://packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LSN-0081-1.html
http://packetstormsecurity.com/files/164437/Netfilter-x_tables-Heap-Out-Of-Bounds-Write-Privilege-Escalation.html
http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d
https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528
https://security.netapp.com/advisory/ntap-20210805-0010/
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22555

Vulnerability Database

314,373

CVE-2021-22555

Deep Security Visibility Without the Complexity