A locking inconsistency issue was discovered in the tty subsystem of the Linux kernel…
Priority LOW 21CWE-416Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- 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.
Summary
A locking inconsistency issue was discovered in the tty subsystem of the Linux kernel through 5.9.13. drivers/tty/tty_io.c and drivers/tty/tty_jobctrl.c may allow a read-after-free attack against TIOCGSID, aka CID-c8bcd9c5be24.
Why it matters now
EPSS 0.00474 41st percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 19
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | up to 5.9.13 | Vulnerable | Linux |
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | 32 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:o:broadcom:fabric_operating_system:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Broadcom |
| cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:solidfire_baseboard_management_controller:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions up to 5.9.13 Vulnerable ·Linux
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:o:broadcom:fabric_operating_system:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Broadcom
- cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:solidfire_baseboard_management_controller:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
Show 9 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:a700s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:a700s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:8300_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:8300:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:8700_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:8700:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:a400_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:a400:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
- cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:a700s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:a700s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:8300_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:8300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:8700_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:8700:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:a400_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:a400:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
Remediation
Red Hat 2 advisories
- RHSA-2021:4356 Released 2021-11-09 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-348.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-348.el8, kernel-4.18.0-348.el8, kernel-abi-stablelists-4.18.0-348.el8 +19
- RHSA-2021:4140 Released 2021-11-09 · Red Hat rating Moderatekernel-rt security and bug fix update
- Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-348.rt7.130.el8, kernel-rt-core-4.18.0-348.rt7.130.el8, kernel-rt-debug-4.18.0-348.rt7.130.el8 +7
- Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-348.rt7.130.el8, kernel-rt-core-4.18.0-348.rt7.130.el8, kernel-rt-debug-4.18.0-348.rt7.130.el8 +9
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 yet: Fix deferred |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2021:4356 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2021:4356 |
| Red Hat Enterprise Linux Real Time (v. 8) | Fixed | RHSA-2021:4140 |
| Red Hat Enterprise Linux Real Time for NFV (v. 8) | Fixed | RHSA-2021:4140 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2020-29660
- 2026-10-03 Alias added: GHSA-6v44-4w2g-hxp9
- 2026-11-07 Fix available: Red Hat CodeReady Linux Builder (v. 8), Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux Real Time (v. 8) +1 · Red Hat
- 2026-11-07 CVSS score added · Red Hat
References
Exploit 2
Sources
- CVE-2020-29660 · CVE Program
- CVE-2020-29660 · NVD
- FIRST EPSS
- GHSA-6v44-4w2g-hxp9 · GitHub Advisory Database · CC BY 4.0
- CVE-2020-29660 · Red Hat security data · CC BY 4.0
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