--- id: CVE-2021-22555 title: >- A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c 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 severity: high cvss: 8.3 cvssVector: 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H' cwe: - CWE-787 - CWE-787 vendor: netapp product: cloud_backup affected: - c400_firmware - c250_firmware - h410c_firmware - h300s_firmware - h500s_firmware - h700s_firmware - h410s_firmware - 'linux_kernel >= 2.6.19, < 4.4.267' - 'linux_kernel >= 4.5, < 4.9.267' - 'linux_kernel >= 4.10, < 4.14.231' - 'linux_kernel >= 4.15, < 4.19.188' - 'linux_kernel >= 4.20, < 5.4.113' - 'linux_kernel >= 5.5, < 5.10.31' - 'linux_kernel >= 5.11, < 5.12' - fabric_operating_system - fas_8300_firmware - fas_8700_firmware - aff_a400_firmware - aff_a250_firmware - aff_500f_firmware - h610c_firmware - h610s_firmware - h615c_firmware - cloud_backup - hci_management_node - solidfire - solidfire_baseboard_management_controller patched: - linux_kernel 5.12 published: '2021-07-07' updated: '2026-10-13' sourceUpdated: '2026-10-13T18:25:34.177' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-22555' references: - url: >- http://packetstormsecurity.com/files/163528/Linux-Kernel-Netfilter-Heap-Out-Of-Bounds-Write.html label: cve-coordination@google.com - url: >- http://packetstormsecurity.com/files/163878/Kernel-Live-Patch-Security-Notice-LSN-0080-1.html label: cve-coordination@google.com - url: >- http://packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LSN-0081-1.html label: cve-coordination@google.com - url: >- http://packetstormsecurity.com/files/164437/Netfilter-x_tables-Heap-Out-Of-Bounds-Write-Privilege-Escalation.html label: cve-coordination@google.com - url: >- http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html label: cve-coordination@google.com - url: >- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21 label: cve-coordination@google.com - url: >- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d label: cve-coordination@google.com - url: >- https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528 label: cve-coordination@google.com - url: 'https://security.netapp.com/advisory/ntap-20210805-0010/' label: cve-coordination@google.com - url: >- http://packetstormsecurity.com/files/163528/Linux-Kernel-Netfilter-Heap-Out-Of-Bounds-Write.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- http://packetstormsecurity.com/files/163878/Kernel-Live-Patch-Security-Notice-LSN-0080-1.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- http://packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LSN-0081-1.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- http://packetstormsecurity.com/files/164437/Netfilter-x_tables-Heap-Out-Of-Bounds-Write-Privilege-Escalation.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21 label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528 label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.netapp.com/advisory/ntap-20210805-0010/' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22555 label: 134c704f-9b21-4f2e-91b3-4a467353bcc0 tags: - nvd - kev - in-the-wild - exploit-available epss: 0.78684 epssPercentile: 0.99583 kev: true kevDateAdded: '2025-10-06' kevDueDate: '2025-10-27' kevRansomware: false exploited: true exploits: exploitdb: true github: 13 githubRepos: - 'https://github.com/JoneyJunior/cve-2021-22555' - 'https://github.com/xyjl-ly/CVE-2021-22555-Exploit' - 'https://github.com/cgwalters/container-cve-2021-22555' metasploit: - exploit/linux/local/netfilter_xtables_heap_oob_write_priv_esc checkedAt: '2026-10-13T18:42:17.250Z' exploitAvailable: true ingestedAt: '2026-10-13T18:41:42.717Z' --- ## Overview 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 - `c400_firmware` - `c250_firmware` - `h410c_firmware` - `h300s_firmware` - `h500s_firmware` - `h700s_firmware` - `h410s_firmware` - `linux_kernel >= 2.6.19, < 4.4.267` - `linux_kernel >= 4.5, < 4.9.267` - `linux_kernel >= 4.10, < 4.14.231` - `linux_kernel >= 4.15, < 4.19.188` - `linux_kernel >= 4.20, < 5.4.113` - `linux_kernel >= 5.5, < 5.10.31` - `linux_kernel >= 5.11, < 5.12` - `fabric_operating_system` - `fas_8300_firmware` - `fas_8700_firmware` - `aff_a400_firmware` - `aff_a250_firmware` - `aff_500f_firmware` - `h610c_firmware` - `h610s_firmware` - `h615c_firmware` - `cloud_backup` - `hci_management_node` - `solidfire` - `solidfire_baseboard_management_controller` ## Remediation Upgrade past the affected range: - `linux_kernel 5.12`