Use after free in gnutls
Priority MEDIUM 48CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
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 gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.
Why it matters now
EPSS 0.03678 89th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Red Hat: 1 advisory
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 |
|---|---|---|---|---|---|
| — | gnutls | gnutls 3.7.1 | — | No fix listed | CNA |
- gnutls Vendor— Affected gnutls 3.7.1 Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:* | 3.6.3 to before 3.7.1 | Vulnerable | GNU |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
| cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
- cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:* Versions 3.6.3 to before 3.7.1 Vulnerable ·GNU
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
- cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:a:netapp:e-series_performance_analyzer:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
Remediation
Red Hat 1 advisory
- RHSA-2021:4451 Released 2021-11-09 · Red Hat rating Moderategnutls and nettle security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) gnutls-c++-3.6.16-4.el8, gnutls-dane-3.6.16-4.el8, gnutls-devel-3.6.16-4.el8 +2
- Red Hat Enterprise Linux BaseOS (v. 8) gnutls-3.6.16-4.el8, nettle-3.4.1-7.el8
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
gnutls — FEDORA-2021-18bef34f05
2 records Highest priority Priority MEDIUM 2 MEDIUM
Other records, highest priority first
- TI-2021-03527 Use after free in gnutlsPriority MEDIUM 55
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2021:4451 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2021:4451 |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20231
- 2026-10-03 Alias added: GHSA-mqq9-xchh-h97q
References
Other 8
- [spark-issues] 20210413 [jira] [Created] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210417 [jira] [Commented] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210423 [jira] [Resolved] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210425 [jira] [Commented] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210426 [jira] [Commented] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210426 [jira] [Updated] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210429 [jira] [Commented] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
- [spark-issues] 20210430 [jira] [Commented] (SPARK-35054) Getting Critical Vulnerability CVE-2021-20231 on spark 3.0.0 branch
Sources
- CVE-2021-20231 · CVE Program
- CVE-2021-20231 · NVD
- FIRST EPSS
- GHSA-mqq9-xchh-h97q · GitHub Advisory Database · CC BY 4.0
- CVE-2021-20231 · 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