CVE-2021-4209
A NULL pointer dereference flaw was found in GnuTLS.
Published Aug 24, 2022 · updated Oct 14, 2026 · gnu gnutls
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.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Aug 24, 2022 · NIST NVD
Detected
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.
Oct 14, 2026 · NIST NVD
Updated
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.
Affected
- cpe gnu/gnutlsversion unspecified
- cpe netapp/active iq unified managerversion unspecified
- cpe netapp/hci bootstrap osversion unspecified
- cpe netapp/solidfire & hci management nodeversion unspecified
- cpe redhat/enterprise linux8.0
Sources
- CVE.orgVulnerability recordCVE-2021-4209
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2021-4209
30-day exploitation probability 1.8%
first.org - NIST NVDVulnerability recordCVE-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.
nvd.nist.gov