Integer overflow in kernel
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
- 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-190 and the CVSS impact.
Summary
A flaw was found in the Linux kernel. A denial of service problem is identified if an extent tree is corrupted in a crafted ext4 filesystem in fs/ext4/extents.c in ext4_es_cache_extent. Fabricating an integer overflow, A local attacker with a special user privilege may cause a system crash problem which can lead to an availability threat.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | kernel | Affects linux kernel before v5.9. | — | No fix listed | CNA |
- kernel Vendor— Affected Affects linux kernel before v5.9. Fixed in — No fix listed CNA
Remediation
Red Hat 2 advisories
- RHSA-2021:1739 Released 2021-05-18 · Red Hat rating Importantkernel-rt security and bug fix update
- Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-305.rt7.72.el8, kernel-rt-core-4.18.0-305.rt7.72.el8, kernel-rt-debug-4.18.0-305.rt7.72.el8 +7
- Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-305.rt7.72.el8, kernel-rt-core-4.18.0-305.rt7.72.el8, kernel-rt-debug-4.18.0-305.rt7.72.el8 +9
- RHSA-2021:1578 Released 2021-05-18 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-305.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-305.el8, kernel-4.18.0-305.el8, kernel-abi-stablelists-4.18.0-305.el8 +19
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2021:1578 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2021:1578 |
| Red Hat Enterprise Linux Real Time (v. 8) | Fixed | RHSA-2021:1739 |
| Red Hat Enterprise Linux Real Time for NFV (v. 8) | Fixed | RHSA-2021:1739 |
Not affected: 3 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3428
- 2026-10-03 Alias added: GHSA-g9vc-85jh-rm36
References
More Linux Kernel vulnerabilities
- 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
Sources
- CVE-2021-3428 · CVE Program
- CVE-2021-3428 · NVD
- FIRST EPSS
- GHSA-g9vc-85jh-rm36 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3428 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences