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TI-2021-02686 Aliases CVE-2021-3753

Out-of-bounds read in kernel

Priority LOW 22CWE-125Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
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-125 and the CVSS impact.

Summary

A race problem was seen in the vt_k_ioctl in drivers/tty/vt/vt_ioctl.c in the Linux kernel, which may cause an out of bounds read in vt as the write access to vc_mode is not protected by lock-in vt_ioctl (KDSETMDE). The highest threat from this vulnerability is to data confidentiality.

Why it matters now

EPSS 0.00364 30th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
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
—kernelLinux kernel 5.15-rc1—No fix listedCNA
  • kernel Vendor— Affected Linux kernel 5.15-rc1 Fixed in — No fix listed CNA

CPE configurations NVD · 19

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 5.15VulnerableLinux
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*not specified by NVDVulnerableNetApp
cpe:2.3:a:netapp:element_software:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
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:o:netapp:bootstrap_os:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:h:netapp:hci_compute_node:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.15 Vulnerable ·Linux
  • cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:a:netapp:element_software:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • 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:o:netapp:bootstrap_os:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:h:netapp:hci_compute_node:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
  • cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
Show 9 more CPE
CPEVersionsRoleVendor
cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:*not specified by NVDRunning onNetApp
  • cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
  • cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
  • cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
  • cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
  • cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
  • cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp

Remediation

Red Hat 2 advisories

  • RHSA-2024:2950 Released 2024-05-22 · Red Hat rating Moderate
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.rt7.342.el8_10, kernel-rt-core-4.18.0-553.rt7.342.el8_10, kernel-rt-debug-4.18.0-553.rt7.342.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.rt7.342.el8_10, kernel-rt-core-4.18.0-553.rt7.342.el8_10, kernel-rt-debug-4.18.0-553.rt7.342.el8_10 +7
  • RHSA-2024:3138 Released 2024-05-22 · Red Hat rating Moderate
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.el8_10, kernel-4.18.0-553.el8_10, kernel-abi-stablelists-4.18.0-553.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.el8_10

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 Enterprise Linux BaseOS (v. 8)Fixed RHSA-2024:3138
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2024:3138
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2024:2950
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2024:2950
Not affected: 3 products
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-3753

References

Sources