CVE-2021-4209

A NULL pointer dereference flaw was found in GnuTLS. As Nettle's hash update functions internally call memcpy, providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances.

CVSS 3.1

6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

1.9% chance of exploitation in the next 30 days; higher than 79% of CVEs (scores of 2026-10-25)

CWE

CWE-476

Published

2022-08-24

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• gnu:gnutls
• netapp:active_iq_unified_manager
• netapp:hci_bootstrap_os
• netapp:solidfire_\&_hci_management_node
• redhat:enterprise_linux

References

• https://access.redhat.com/security/cve/CVE-2021-4209
• https://bugzilla.redhat.com/show_bug.cgi?id=2044156
• https://gitlab.com/gnutls/gnutls/-/commit/3db352734472d851318944db13be73da61300568
• https://gitlab.com/gnutls/gnutls/-/issues/1306
• https://gitlab.com/gnutls/gnutls/-/merge_requests/1503

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