NULL pointer dereference in GnuTLS - CVE-2020-24659

Vulnerability identifier: #VU46295

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-24659

CWE-ID: CWE-476

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure. A remote attacker can perform a denial of service (DoS) attack.

GnuTLS
Gentoo Linux
Red Hat Enterprise Linux Server
Anolis OS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Opensuse
openEuler
Ubuntu
Fedora
Quay
Red Hat OpenShift Serverless
gnutls (Alpine package)
libgnutls30 (Ubuntu package)
gnutls
gnutls-devel
gnutls-debugsource
gnutls-debuginfo
gnutls-help
gnutls (Red Hat package)
mingw-gnutls
gnutls-c++
gnutls-dane
gnutls-utils
Red Hat Ceph Storage

Update to version 3.6.15.

GnuTLS - update to 3.6.15
Quay - update to 3.3.3
gnutls (Alpine package) - update to 3.6.15-r0
Red Hat OpenShift Serverless - update to 1.12.0
libgnutls30 (Ubuntu package) - update to 3.6.13-2ubuntu1.3
gnutls - update to 3.6.14-6
gnutls-devel - update to 3.6.14-6
gnutls-debugsource - update to 3.6.14-6
gnutls-debuginfo - update to 3.6.14-6
gnutls-help - update to 3.6.14-6
gnutls (Red Hat package) - update to 3.6.14-7.el8_3
mingw-gnutls - addressed in versions 3.6.15-1.fc32, 3.6.15-1.fc33
gnutls - update to 3.6.16-5.0.1
gnutls-c++ - update to 3.6.16-5.0.1
gnutls-dane - update to 3.6.16-5.0.1
gnutls-devel - update to 3.6.16-5.0.1
gnutls-utils - update to 3.6.16-5.0.1

• https://gitlab.com/gnutls/gnutls/-/issues/1071
• https://security.gentoo.org/glsa/202009-01
• https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-09-04

• NULL pointer dereference in GnuTLS
• NULL pointer dereference in gnutls (Alpine package)
• Gentoo update for GnuTLS
• OpenSUSE Linux update for gnutls
• OpenSUSE Linux update for gnutls
• Red Hat Enterprise Linux 8 update for gnutls
• Multiple vulnerabilities in Red Hat Quay
• Red Hat update for Red Hat Ceph Storage 4.2
• Multiple vulnerabilities in Red Hat OpenShift Serverless
• openEuler 20.03 LTS update for gnutls
• Anolis OS update for gnutls
• Ubuntu update for gnutls28
• Fedora 33 update for mingw-gnutls
• Fedora 32 update for mingw-gnutls