What’s Vulnerable › Vulnerabilities
CVE-2021-22555: Linux Kernel Heap Out-of-Bounds Write Vulnerability
- Severity: high (CVSS 7.8 v3.1)
- Exploited in the wild: yes — in CISA KEV since 2025-10-06
- EPSS: 78.7% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2021-07-07 · updated 2026-10-13
- Weakness: CWE-787
Description
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
Affected products
- Brocade Fabric OS: all versions
- Linux kernel: from 2.6.19 before 4.4.267; from 4.5 before 4.9.267; from 4.10 before 4.14.231; from 4.15 before 4.19.188; from 4.20 before 5.4.113; from 5.5 before 5.10.31 — fixed in 4.14.231, 4.19.188, 4.4.267, 4.9.267, 5.10.31, 5.12
- NetApp Aff 500F Firmware: all versions
- NetApp Aff A250 Firmware: all versions
- NetApp Aff A400 Firmware: all versions
- NetApp C250 Firmware: all versions
- NetApp C400 Firmware: all versions
- NetApp Cloud Backup: all versions
- NetApp Fas 8300 Firmware: all versions
- NetApp Fas 8700 Firmware: all versions
- NetApp H300S Firmware: all versions
- NetApp H410C Firmware: all versions
- NetApp H410S Firmware: all versions
- NetApp H500S Firmware: all versions
- NetApp H610C Firmware: all versions
- NetApp H610S Firmware: all versions
- NetApp H615C Firmware: all versions
- NetApp H700S Firmware: all versions
- NetApp Hci Management Node: all versions
- NetApp Solidfire: all versions
- NetApp Solidfire Baseboard Management Controller: all versions
How to fix
Upgrade to a fixed version: Linux kernel 4.14.231, 4.19.188, 4.4.267, 4.9.267. Check the vendor advisory for mitigations.
References
- 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/
- 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
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