Use after free in kernel
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 4 fixed, 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
A flaw was found in the Linux kernel’s implementation of MIDI, where an attacker with a local account and the permissions to issue ioctl commands to midi devices could trigger a use-after-free issue. A write to this specific memory while freed and before use causes the flow of execution to change and possibly allow for memory corruption or privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
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 | kernel 5.7-rc6 | — | No fix listed | CNA |
- kernel Vendor— Affected kernel 5.7-rc6 Fixed in — No fix listed CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.4.224; 4.5 to before 4.9.224; 4.10 to before 4.14.181; 4.15 to before 4.19.124; 4.20 to before 5.4.42; 5.5 to before 5.6.14 | Vulnerable | Linux |
| cpe:2.3:a:redhat:openshift_container_platform:4.4:*:*:*:*:*:*:* | 4.4 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:openshift_container_platform:4.5:*:*:*:*:*:*:* | 4.5 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:* | 4.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_mrg:2.0:*:*:*:*:*:*:* | 2.0 | Vulnerable | Red Hat |
| cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:solidfire_baseboard_management_controller:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.4.224; 4.5 to before 4.9.224; 4.10 to before 4.14.181; 4.15 to before 4.19.124; 4.20 to before 5.4.42; 5.5 to before 5.6.14 Vulnerable ·Linux
- cpe:2.3:a:redhat:openshift_container_platform:4.4:*:*:*:*:*:*:* Versions 4.4 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:openshift_container_platform:4.5:*:*:*:*:*:*:* Versions 4.5 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:* Versions 4.6 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:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_mrg:2.0:*:*:*:*:*:*:* Versions 2.0 Vulnerable ·Red Hat
- cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:solidfire_baseboard_management_controller:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
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: Will not fix |
| Red Hat Enterprise MRG 2 | 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: 2 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2020-27786
- 2026-10-03 Alias added: GHSA-3mfq-6299-p3w3
References
Patch 2
Sources
- CVE-2020-27786 · CVE Program
- CVE-2020-27786 · NVD
- FIRST EPSS
- GHSA-3mfq-6299-p3w3 · GitHub Advisory Database · CC BY 4.0
- CVE-2020-27786 · 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