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TI-2021-13218 Aliases CVE-2021-33909GHSA-6g4v-3wmh-w3jg

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly…

Priority MEDIUM 46CWE-190Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 44 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.

Summary

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.

Why it matters now

EPSS 0.09808 95th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Partial Red Hat: 21 advisoriesRed Hat: 44 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 12

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*3.12.43 to before 3.13; 3.16 to before 4.4.276; 4.5 to before 4.9.276; 4.10 to before 4.14.240; 4.15 to before 4.19.198; 4.20 to before 5.4.134; 5.5 to before 5.10.52; 5.11 to before 5.12.19; 5.13 to before 5.13.4VulnerableLinux
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:a:oracle:communications_session_border_controller:8.2:*:*:*:*:*:*:*8.2VulnerableOracle
cpe:2.3:a:oracle:communications_session_border_controller:8.3:*:*:*:*:*:*:*8.3VulnerableOracle
cpe:2.3:a:oracle:communications_session_border_controller:8.4:*:*:*:*:*:*:*8.4VulnerableOracle
cpe:2.3:a:oracle:communications_session_border_controller:9.0:*:*:*:*:*:*:*9.0VulnerableOracle
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.12.43 to before 3.13; 3.16 to before 4.4.276; 4.5 to before 4.9.276; 4.10 to before 4.14.240; 4.15 to before 4.19.198; 4.20 to before 5.4.134; 5.5 to before 5.10.52; 5.11 to before 5.12.19; 5.13 to before 5.13.4 Vulnerable ·Linux
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:a:oracle:communications_session_border_controller:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:communications_session_border_controller:8.3:*:*:*:*:*:*:* Versions 8.3 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:communications_session_border_controller:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Oracle
  • cpe:2.3:a:oracle:communications_session_border_controller:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Oracle
Show 2 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:sonicwall:sma1000_firmware:*:*:*:*:*:*:*:*up to 12.4.2-02044VulnerableSonicWall
cpe:2.3:h:sonicwall:sma1000:-:*:*:*:*:*:*:*not specified by NVDRunning onSonicWall
  • cpe:2.3:o:sonicwall:sma1000_firmware:*:*:*:*:*:*:*:* Versions up to 12.4.2-02044 Vulnerable ·SonicWall
  • cpe:2.3:h:sonicwall:sma1000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·SonicWall

Remediation

Red Hat 21 advisories

  • RHSA-2021:2736 Released 2021-07-22 · Red Hat rating Important
    Red Hat Virtualization Host security and bug fix update [ovirt-4.4.7]
    • Red Hat Virtualization 4 Hypervisor for RHEL 8 redhat-virtualization-host-4.4.7-20210715.1.el8_4, redhat-virtualization-host-image-update-4.4.7-20210715.1.el8_4
  • RHSA-2021:2737 Released 2021-07-21 · Red Hat rating Important
    RHV-H security update (redhat-virtualization-host) 4.3.17
    • RHEL 7-based RHEV-H for RHEV 4 (build requirements) redhat-virtualization-host-4.3.17-20210713.0.el7_9, redhat-virtualization-host-image-update-4.3.17-20210713.0.el7_9
    • Red Hat Virtualization 4 Hypervisor for RHEL 7 redhat-virtualization-host-4.3.17-20210713.0.el7_9, redhat-virtualization-host-image-update-4.3.17-20210713.0.el7_9
  • RHSA-2021:2728 Released 2021-07-21 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) bpftool-3.10.0-1062.52.2.el7, kernel-3.10.0-1062.52.2.el7, kernel-abi-whitelists-3.10.0-1062.52.2.el7 +8
    • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) kernel-tools-libs-devel-3.10.0-1062.52.2.el7
    • Red Hat Enterprise Linux Server EUS (v. 7.7) bpftool-3.10.0-1062.52.2.el7, kernel-3.10.0-1062.52.2.el7, kernel-abi-whitelists-3.10.0-1062.52.2.el7 +11
    • Red Hat Enterprise Linux Server Optional EUS (v. 7.7) kernel-debug-devel-3.10.0-1062.52.2.el7, kernel-tools-libs-devel-3.10.0-1062.52.2.el7
Show 18 more Red Hat advisories
  • RHSA-2021:2725 Released 2021-07-21 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux Client (v. 7) bpftool-3.10.0-1160.36.2.el7, kernel-3.10.0-1160.36.2.el7, kernel-abi-whitelists-3.10.0-1160.36.2.el7 +8
    • Red Hat Enterprise Linux Client Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.36.2.el7
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.36.2.el7
    • Red Hat Enterprise Linux Server (v. 7) bpftool-3.10.0-1160.36.2.el7, kernel-3.10.0-1160.36.2.el7, kernel-abi-whitelists-3.10.0-1160.36.2.el7 +11
    • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debug-devel-3.10.0-1160.36.2.el7, kernel-tools-libs-devel-3.10.0-1160.36.2.el7
    • Red Hat Enterprise Linux Workstation (v. 7) bpftool-3.10.0-1160.36.2.el7, kernel-3.10.0-1160.36.2.el7, kernel-abi-whitelists-3.10.0-1160.36.2.el7 +8
    • Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.36.2.el7
  • RHSA-2021:2726 Released 2021-07-21 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt-3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debug-3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debug-devel-3.10.0-1160.36.2.rt56.1179.el7 +4
    • Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt-3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debug-3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debug-devel-3.10.0-1160.36.2.rt56.1179.el7 +7
  • RHSA-2021:2729 Released 2021-07-21 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux Server EUS (v. 7.7) kpatch-patch-3_10_0-1062_30_1-1-4.el7, kpatch-patch-3_10_0-1062_31_2-1-4.el7, kpatch-patch-3_10_0-1062_31_3-1-4.el7 +9
  • RHSA-2021:2716 Released 2021-07-21 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux BaseOS (v. 8) kpatch-patch-4_18_0-305-1-3.el8, kpatch-patch-4_18_0-305_3_1-1-2.el8_4, kpatch-patch-4_18_0-305_7_1-1-1.el8_4
  • RHSA-2021:2720 Released 2021-07-21 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) kpatch-patch-4_18_0-193_13_2-1-10.el8_2, kpatch-patch-4_18_0-193_14_3-1-10.el8_2, kpatch-patch-4_18_0-193_19_1-1-10.el8_2 +9
  • RHSA-2021:2731 Released 2021-07-21 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux Server E4S (v. 7.6) kpatch-patch-3_10_0-957_58_2-1-4.el7, kpatch-patch-3_10_0-957_61_1-1-4.el7, kpatch-patch-3_10_0-957_61_2-1-4.el7 +6
  • RHSA-2021:2727 Released 2021-07-20 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux Server (v. 7) kpatch-patch-3_10_0-1160-1-7.el7, kpatch-patch-3_10_0-1160_11_1-1-6.el7, kpatch-patch-3_10_0-1160_15_2-1-6.el7 +7
  • RHSA-2021:2714 Released 2021-07-20 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-305.10.2.el8_4
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-305.10.2.el8_4, kernel-4.18.0-305.10.2.el8_4, kernel-abi-stablelists-4.18.0-305.10.2.el8_4 +19
  • RHSA-2021:2723 Released 2021-07-20 · Red Hat rating Important
    kpatch-patch security update
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) kpatch-patch-4_18_0-147_24_2-1-11.el8_1, kpatch-patch-4_18_0-147_27_1-1-11.el8_1, kpatch-patch-4_18_0-147_32_1-1-9.el8_1 +6
  • RHSA-2021:2718 Released 2021-07-20 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat CodeReady Linux Builder EUS (v. 8.2) kernel-tools-libs-devel-4.18.0-193.60.2.el8_2
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) bpftool-4.18.0-193.60.2.el8_2, kernel-4.18.0-193.60.2.el8_2, kernel-abi-whitelists-4.18.0-193.60.2.el8_2 +19
  • RHSA-2021:2730 Released 2021-07-20 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux Server AUS (v. 7.6) bpftool-3.10.0-957.78.2.el7, kernel-3.10.0-957.78.2.el7, kernel-abi-whitelists-3.10.0-957.78.2.el7 +8
    • Red Hat Enterprise Linux Server E4S (v. 7.6) kernel-3.10.0-957.78.2.el7, kernel-abi-whitelists-3.10.0-957.78.2.el7, kernel-bootwrapper-3.10.0-957.78.2.el7 +8
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.6) kernel-tools-libs-devel-3.10.0-957.78.2.el7
    • Red Hat Enterprise Linux Server Optional E4S (v. 7.6) kernel-debug-devel-3.10.0-957.78.2.el7, kernel-tools-libs-devel-3.10.0-957.78.2.el7
    • Red Hat Enterprise Linux Server Optional TUS (v. 7.6) kernel-tools-libs-devel-3.10.0-957.78.2.el7
    • Red Hat Enterprise Linux Server TUS (v. 7.6) bpftool-3.10.0-957.78.2.el7, kernel-3.10.0-957.78.2.el7, kernel-abi-whitelists-3.10.0-957.78.2.el7 +8
  • RHSA-2021:2719 Released 2021-07-20 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux Real Time EUS (v. 8.2) kernel-rt-4.18.0-193.60.2.rt13.112.el8_2, kernel-rt-core-4.18.0-193.60.2.rt13.112.el8_2, kernel-rt-debug-4.18.0-193.60.2.rt13.112.el8_2 +7
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2) kernel-rt-4.18.0-193.60.2.rt13.112.el8_2, kernel-rt-core-4.18.0-193.60.2.rt13.112.el8_2, kernel-rt-debug-4.18.0-193.60.2.rt13.112.el8_2 +9
  • RHSA-2021:2722 Released 2021-07-20 · Red Hat rating Important
    kernel security update
    • Red Hat CodeReady Linux Builder EUS (v. 8.1) kernel-tools-libs-devel-4.18.0-147.51.2.el8_1
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) bpftool-4.18.0-147.51.2.el8_1, kernel-4.18.0-147.51.2.el8_1, kernel-abi-whitelists-4.18.0-147.51.2.el8_1 +19
  • RHSA-2021:2732 Released 2021-07-20 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Server AUS (v. 7.4) kernel-3.10.0-693.90.2.el7, kernel-abi-whitelists-3.10.0-693.90.2.el7, kernel-debug-3.10.0-693.90.2.el7 +7
    • Red Hat Enterprise Linux Server E4S (v. 7.4) kernel-3.10.0-693.90.2.el7, kernel-abi-whitelists-3.10.0-693.90.2.el7, kernel-bootwrapper-3.10.0-693.90.2.el7 +8
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.4) kernel-tools-libs-devel-3.10.0-693.90.2.el7
    • Red Hat Enterprise Linux Server Optional E4S (v. 7.4) kernel-debug-devel-3.10.0-693.90.2.el7, kernel-tools-libs-devel-3.10.0-693.90.2.el7
    • Red Hat Enterprise Linux Server Optional TUS (v. 7.4) kernel-tools-libs-devel-3.10.0-693.90.2.el7
    • Red Hat Enterprise Linux Server TUS (v. 7.4) kernel-3.10.0-693.90.2.el7, kernel-abi-whitelists-3.10.0-693.90.2.el7, kernel-debug-3.10.0-693.90.2.el7 +7
  • RHSA-2021:2735 Released 2021-07-20 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Server (v. 6 ELS) kernel-2.6.32-754.41.2.el6, kernel-abi-whitelists-2.6.32-754.41.2.el6, kernel-debug-2.6.32-754.41.2.el6 +7
    • Red Hat Enterprise Linux Server Optional (v. 6 ELS) python-perf-2.6.32-754.41.2.el6
  • RHSA-2021:2715 Released 2021-07-20 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-305.10.2.rt7.83.el8_4, kernel-rt-core-4.18.0-305.10.2.rt7.83.el8_4, kernel-rt-debug-4.18.0-305.10.2.rt7.83.el8_4 +7
    • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-305.10.2.rt7.83.el8_4, kernel-rt-core-4.18.0-305.10.2.rt7.83.el8_4, kernel-rt-debug-4.18.0-305.10.2.rt7.83.el8_4 +9
  • RHSA-2021:2733 Released 2021-07-20 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux Server AUS (v. 7.3) kernel-3.10.0-514.90.2.el7, kernel-abi-whitelists-3.10.0-514.90.2.el7, kernel-debug-3.10.0-514.90.2.el7 +7
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.3) kernel-tools-libs-devel-3.10.0-514.90.2.el7
  • RHSA-2021:2734 Released 2021-07-20 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux Server AUS (v. 7.2) kernel-3.10.0-327.98.2.el7, kernel-abi-whitelists-3.10.0-327.98.2.el7, kernel-debug-3.10.0-327.98.2.el7 +7
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.2) kernel-tools-libs-devel-3.10.0-327.98.2.el7

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
RHEL 7-based RHEV-H for RHEV 4 (build requirements)Fixed RHSA-2021:2737
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:2714
Red Hat CodeReady Linux Builder EUS (v. 8.1)Fixed RHSA-2021:2722
Red Hat CodeReady Linux Builder EUS (v. 8.2)Fixed RHSA-2021:2718
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:2714, RHSA-2021:2716
Red Hat Enterprise Linux BaseOS EUS (v. 8.1)Fixed RHSA-2021:2722, RHSA-2021:2723
Red Hat Enterprise Linux BaseOS EUS (v. 8.2)Fixed RHSA-2021:2718, RHSA-2021:2720
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2021:2725
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2021:2725
Red Hat Enterprise Linux ComputeNode EUS (v. 7.7)Fixed RHSA-2021:2728
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2021:2725
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7)Fixed RHSA-2021:2728
Red Hat Enterprise Linux Real Time (v. 8)Fixed RHSA-2021:2715
Red Hat Enterprise Linux Real Time EUS (v. 8.2)Fixed RHSA-2021:2719
Red Hat Enterprise Linux Real Time for NFV (v. 8)Fixed RHSA-2021:2715
Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2)Fixed RHSA-2021:2719
Red Hat Enterprise Linux Server (v. 6 ELS)Fixed RHSA-2021:2735
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:2725, RHSA-2021:2727
Red Hat Enterprise Linux Server AUS (v. 7.2)Fixed RHSA-2021:2734
Red Hat Enterprise Linux Server AUS (v. 7.3)Fixed RHSA-2021:2733
Red Hat Enterprise Linux Server AUS (v. 7.4)Fixed RHSA-2021:2732
Red Hat Enterprise Linux Server AUS (v. 7.6)Fixed RHSA-2021:2730
Red Hat Enterprise Linux Server E4S (v. 7.4)Fixed RHSA-2021:2732
Red Hat Enterprise Linux Server E4S (v. 7.6)Fixed RHSA-2021:2730, RHSA-2021:2731
Red Hat Enterprise Linux Server EUS (v. 7.7)Fixed RHSA-2021:2728, RHSA-2021:2729
Red Hat Enterprise Linux Server Optional (v. 6 ELS)Fixed RHSA-2021:2735
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2021:2725
Red Hat Enterprise Linux Server Optional AUS (v. 7.2)Fixed RHSA-2021:2734
Red Hat Enterprise Linux Server Optional AUS (v. 7.3)Fixed RHSA-2021:2733
Red Hat Enterprise Linux Server Optional AUS (v. 7.4)Fixed RHSA-2021:2732
Red Hat Enterprise Linux Server Optional AUS (v. 7.6)Fixed RHSA-2021:2730
Red Hat Enterprise Linux Server Optional E4S (v. 7.4)Fixed RHSA-2021:2732
Red Hat Enterprise Linux Server Optional E4S (v. 7.6)Fixed RHSA-2021:2730
Red Hat Enterprise Linux Server Optional EUS (v. 7.7)Fixed RHSA-2021:2728
Red Hat Enterprise Linux Server Optional TUS (v. 7.4)Fixed RHSA-2021:2732
Red Hat Enterprise Linux Server Optional TUS (v. 7.6)Fixed RHSA-2021:2730
Red Hat Enterprise Linux Server TUS (v. 7.4)Fixed RHSA-2021:2732
Red Hat Enterprise Linux Server TUS (v. 7.6)Fixed RHSA-2021:2730
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:2725
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2021:2725
Red Hat Enterprise Linux for Real Time (v. 7)Fixed RHSA-2021:2726
Red Hat Enterprise Linux for Real Time for NFV (v. 7)Fixed RHSA-2021:2726
Red Hat Virtualization 4 Hypervisor for RHEL 7Fixed RHSA-2021:2737
Red Hat Virtualization 4 Hypervisor for RHEL 8Fixed RHSA-2021:2736
Not affected: 5 products
  • RHEL 7-based RHEV-H for RHEV 4 (build requirements)
  • RHEL 8-based RHEV-H for RHEV 4 (build requirements)
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 9
  • Red Hat Virtualization 4 Hypervisor for RHEL 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-33909
  2. 2026-10-03 Alias added: GHSA-6g4v-3wmh-w3jg

References

Exploit 2

Patch 3

Advisory 15

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences