Improper access control in kernel
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-284.
Summary
A flaw was found in the way the dumpable flag setting was handled when certain SUID binaries executed its descendants. The prerequisite is a SUID binary that sets real UID equal to effective UID, and real GID equal to effective GID. The descendant will then have a dumpable value set to 1. As a result, if the descendant process crashes and core_pattern is set to a relative value, its core dump is stored in the current directory with uid:gid permissions. An unprivileged local user with eligible root SUID binary could use this flaw to place core dumps into root-owned directories, potentially resulting in escalation of privileges.
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 | Not Known | — | No fix listed | CNA |
- kernel Vendor— Affected Not Known Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
| cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
- cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
- cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3864
- 2026-10-03 Alias added: GHSA-9682-f2fr-3h46
References
Advisory 2
Sources
- CVE-2021-3864 · CVE Program
- CVE-2021-3864 · NVD
- FIRST EPSS
- GHSA-9682-f2fr-3h46 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3864 · 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