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TI-2021-21720 Aliases CVE-2021-47055GHSA-x2mc-jwgp-h2fq

mtd: require write permissions for locking and badblock ioctls

Priority LOW 31CWE-667Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · High
Fix status
Partial Red Hat: 4 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: mtd: require write permissions for locking and badblock ioctls MEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require write permission. Depending on the hardware MEMLOCK might even be write-once, e.g. for SPI-NOR flashes with their WP# tied to GND. OTPLOCK is always write-once. MEMSETBADBLOCK modifies the bad block table.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00198 9th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.4.269, 4.9.269, 4.14.233 +8Red Hat: 2 advisoriesRed Hat: 4 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.4.233 to before 4.4.269; 4.9.233 to before 4.9.269; 4.14.194 to before 4.14.233; 4.19.139 to before 4.19.191; 5.4.58 to before 5.4.119; 5.7.15 to before 5.8; 5.8.1 to before 5.94.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.8, 5.9Patch availableCNA
LinuxLinux5.9 and later4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13Patch availableCNA
  • Linux VendorLinux Affected 4.4.233 to before 4.4.269; 4.9.233 to before 4.9.269; 4.14.194 to before 4.14.233; 4.19.139 to before 4.19.191; 5.4.58 to before 5.4.119; 5.7.15 to before 5.8; 5.8.1 to before 5.9 Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.8, 5.9 Patch available CNA
  • Linux VendorLinux Affected 5.9 and later Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.4.233 to before 4.4.269; 4.9.233 to before 4.9.269; 4.14.194 to before 4.14.233; 4.19.139 to before 4.19.191; 5.4.58 to before 5.4.119; 5.9 to before 5.10.37; 5.11 to before 5.11.21; 5.12 to before 5.12.4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.4.233 to before 4.4.269; 4.9.233 to before 4.9.269; 4.14.194 to before 4.14.233; 4.19.139 to before 4.19.191; 5.4.58 to before 5.4.119; 5.9 to before 5.10.37; 5.11 to before 5.11.21; 5.12 to before 5.12.4 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.8, 5.9
  • Fix · CNA Linux (Linux) Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13

Red Hat 2 advisories

  • RHSA-2024:3627 Released 2024-06-05 · Red Hat rating Moderate
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-core-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-4.18.0-553.5.1.rt7.346.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-core-4.18.0-553.5.1.rt7.346.el8_10, kernel-rt-debug-4.18.0-553.5.1.rt7.346.el8_10 +7
  • RHSA-2024:3618 Released 2024-06-05 · Red Hat rating Moderate
    kernel update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.5.1.el8_10, kernel-4.18.0-553.5.1.el8_10, kernel-abi-stablelists-4.18.0-553.5.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.5.1.el8_10

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2024:3618
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2024:3618
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2024:3627
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2024:3627
Not affected: 1 product
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47055
  2. 2026-10-03 Alias added: GHSA-x2mc-jwgp-h2fq

References

Patch 9

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

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