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TI-2021-03492 Aliases CVE-2021-20194GHSA-vw35-vgjr-5jhv

Improper input validation in kernel

Priority LOW 34CWE-20Published · 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: 4 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

Summary

There is a vulnerability in the linux kernel versions higher than 5.2 (if kernel compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered). As result of BPF execution, the local user can trigger bug in __cgroup_bpf_run_filter_getsockopt() function that can lead to heap overflow (because of non-hardened usercopy). The impact of attack could be deny of service or possibly privileges escalation.

Why it matters now

EPSS 0.004 34th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 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
—kernelkernel 5.2 and higher.—No fix listedCNA
  • kernel Vendor— Affected kernel 5.2 and higher. Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*after 5.2VulnerableLinux
cpe:2.3:a:redhat:openshift_container_platform:4.4:*:*:*:*:*:*:*4.4VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.5:*:*:*:*:*:*:*4.5VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:*4.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions after 5.2 Vulnerable ·Linux
  • cpe:2.3:a:redhat:openshift_container_platform:4.4:*:*:*:*:*:*:* Versions 4.4 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.5:*:*:*:*:*:*:* Versions 4.5 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:* Versions 4.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat

Remediation

Red Hat 2 advisories

  • RHSA-2021:4356 Released 2021-11-09 · Red Hat rating Moderate
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-348.el8
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-348.el8, kernel-4.18.0-348.el8, kernel-abi-stablelists-4.18.0-348.el8 +19
  • RHSA-2021:4140 Released 2021-11-09 · Red Hat rating Moderate
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-348.rt7.130.el8, kernel-rt-core-4.18.0-348.rt7.130.el8, kernel-rt-debug-4.18.0-348.rt7.130.el8 +7
    • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-348.rt7.130.el8, kernel-rt-core-4.18.0-348.rt7.130.el8, kernel-rt-debug-4.18.0-348.rt7.130.el8 +9

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:4356
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:4356
Red Hat Enterprise Linux Real Time (v. 8)Fixed RHSA-2021:4140
Red Hat Enterprise Linux Real Time for NFV (v. 8)Fixed RHSA-2021:4140
Not affected: 4 products
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-20194
  2. 2026-10-03 Alias added: GHSA-vw35-vgjr-5jhv

References

Patch 1

Advisory 1

Sources

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