NGINX: Schwachstelle ermöglicht Denial of Service
WID-SEC-2022-0463 · first 26.05.2021 · updated 15.07.2026 · CVSS 7,5
What it is about
NGINX ist eine Webserver-, Reverse Proxy- und E-Mail-Proxy Software. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in NGINX ausnutzen, um einen Denial of Service Angriff durchzuführen.
Under what conditions?
Over the network and without logging in. This is the most dangerous combination: attackers can scan reachable devices automatically.
What can happen in the worst case
An attacker could use the vulnerability to
- einen Denial of Service Angriff durchzuführen
Am I affected?
Affected according to the BSI:
- Debian Linux
- Amazon Linux 2
- Red Hat Enterprise Linux
- Ubuntu Linux
- SUSE Linux
- Oracle Linux
- Gentoo Linux
- Open Source Arch Linux
- Avaya Aura Communication Manager
- Avaya Aura Session Manager
- Avaya Aura Application Enablement Services
- Avaya Aura System Manager
and 6 more
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- NGINX NGINX 1.21.0
- Broadcom Brocade SANnav v2.2.0.2
- Broadcom Brocade SANnav 2.2.1
Is the vulnerability already being exploited?
None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.
Information and sources
- Original BSI advisory (WID)
- [nginx-announce] nginx-1.21.0 vom 2021-05-25 mailman.nginx.org
- Ubuntu Security Notice USN-4967-1 vom 2021-05-26 ubuntu.com
- Gentoo Linux Security Advisory GLSA-202105-38 vom 2021-05-26 security.gentoo.org
- SUSE Security Update SUSE-SU-2021:1792-1 vom 2021-05-27 lists.suse.com
- Ubuntu Security Notice USN-4967-2 vom 2021-05-27 ubuntu.com
- Debian Security Advisory DSA-4921 vom 2021-05-28 www.debian.org
- Debian Security Advisory DLA-2670 vom 2021-05-30 lists.debian.org
- SUSE Security Update SUSE-SU-2021:1815-1 vom 2021-05-31 lists.suse.com
- SUSE Security Update SUSE-SU-2021:1839-1 vom 2021-06-02 lists.suse.com
- Amazon Linux Security Advisory ALAS-2021-1507 vom 2021-06-02 alas.aws.amazon.com
- Red Hat Security Advisory RHSA-2021:2258 vom 2021-06-07 access.redhat.com
- Red Hat Security Advisory RHSA-2021:2278 vom 2021-06-07 access.redhat.com
- Red Hat Security Advisory RHSA-2021:2259 vom 2021-06-07 access.redhat.com
- Red Hat Security Advisory RHSA-2021:2290 vom 2021-06-08 access.redhat.com
- Oracle Linux Security Advisory ELSA-2021-2259 vom 2021-06-08 linux.oracle.com
- Oracle Linux Security Advisory ELSA-2021-2290 vom 2021-06-10 linux.oracle.com
- AVAYA Security Advisory ASA-2021-078 vom 2021-06-10 downloads.avaya.com
- Arch Linux Security Advisory ASA-202106-36 vom 2021-06-15 security.archlinux.org
- Arch Linux Security Advisory ASA-202106-48 vom 2021-06-22 security.archlinux.org
- Exploit CVE-2021-23017 vom 2021-08-30 github.com
- Red Hat Security Advisory RHSA-2021:3653 vom 2021-09-23 access.redhat.com
- Red Hat Security Advisory RHSA-2021:3873 vom 2021-10-15 access.redhat.com
- Red Hat Security Advisory RHSA-2021:3925 vom 2021-10-20 access.redhat.com
- Red Hat Security Advisory RHSA-2021:4618 vom 2021-11-11 access.redhat.com
- Red Hat Security Advisory RHSA-2022:0323 vom 2022-01-31 access.redhat.com
and 11 more sources in the original advisory
CVE: CVE-2021-23017
Source: BSI warning and information service (CERT-Bund); CISA. The assessment of the conditions is my reading of the BSI text; the external pages are in their original language.