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TI-2021-03556 Aliases CVE-2021-20265GHSA-7j7j-cjf4-3c2x

Uncontrolled resource consumption in kernel

Priority LOW 25CWE-400Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-400.

Summary

A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allows an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability.

Why it matters now

EPSS 0.00339 27th percentileScored 2026-11-07
Fix Fixed Red Hat: 3 advisories

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
—kernelLinux kernel 4.5-rc3—No fix listedCNA
  • kernel Vendor— Affected Linux kernel 4.5-rc3 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*not specified by NVDVulnerableLinux
cpe:2.3:a:oracle:tekelec_platform_distribution:*:*:*:*:*:*:*:*7.4.0 – 7.7.1VulnerableOracle
  • cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Linux
  • cpe:2.3:a:oracle:tekelec_platform_distribution:*:*:*:*:*:*:*:* Versions 7.4.0 – 7.7.1 Vulnerable ·Oracle

Remediation

Red Hat 3 advisories

  • RHSA-2021:1288 Released 2021-04-20 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux Server (v. 6 ELS) kernel-2.6.32-754.39.1.el6, kernel-abi-whitelists-2.6.32-754.39.1.el6, kernel-debug-2.6.32-754.39.1.el6 +7
    • Red Hat Enterprise Linux Server Optional (v. 6 ELS) python-perf-2.6.32-754.39.1.el6
  • RHSA-2021:0856 Released 2021-03-16 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux Client (v. 7) bpftool-3.10.0-1160.21.1.el7, kernel-3.10.0-1160.21.1.el7, kernel-abi-whitelists-3.10.0-1160.21.1.el7 +8
    • Red Hat Enterprise Linux Client Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.21.1.el7
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.21.1.el7
    • Red Hat Enterprise Linux Server (v. 7) bpftool-3.10.0-1160.21.1.el7, kernel-3.10.0-1160.21.1.el7, kernel-abi-whitelists-3.10.0-1160.21.1.el7 +11
    • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debug-devel-3.10.0-1160.21.1.el7, kernel-tools-libs-devel-3.10.0-1160.21.1.el7
    • Red Hat Enterprise Linux Workstation (v. 7) bpftool-3.10.0-1160.21.1.el7, kernel-3.10.0-1160.21.1.el7, kernel-abi-whitelists-3.10.0-1160.21.1.el7 +8
    • Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.21.1.el7
  • RHSA-2021:0857 Released 2021-03-16 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt-3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debug-3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debug-devel-3.10.0-1160.21.1.rt56.1158.el7 +4
    • Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt-3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debug-3.10.0-1160.21.1.rt56.1158.el7, kernel-rt-debug-devel-3.10.0-1160.21.1.rt56.1158.el7 +7

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux Server (v. 6 ELS)Fixed RHSA-2021:1288
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux Server Optional (v. 6 ELS)Fixed RHSA-2021:1288
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2021:0856
Red Hat Enterprise Linux for Real Time (v. 7)Fixed RHSA-2021:0857
Red Hat Enterprise Linux for Real Time for NFV (v. 7)Fixed RHSA-2021:0857
Not affected: 3 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-20265
  2. 2026-10-03 Alias added: GHSA-7j7j-cjf4-3c2x

References

Patch 3

Sources

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