NULL pointer dereference in Gnu Gnutls

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 ci…

EPSS: 0.014 (69.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-4209?
CVE-2021-4209 is a medium-severity vulnerability in Gnu Gnutls, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2022-08-24.
How severe is CVE-2021-4209?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-4209 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.