CVEs-PoC/2021/CVE-2021-4209.md

CVE-2021-4209

Description

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.

POC

Reference

• https://gitlab.com/gnutls/gnutls/-/commit/3db352734472d851318944db13be73da61300568
• https://gitlab.com/gnutls/gnutls/-/commit/3db352734472d851318944db13be73da61300568

Github

• https://github.com/ARPSyndicate/cvemon
• https://github.com/GitHubForSnap/ssmtp-gael