CVE-2021-22955 Denial of service in Citrix ADC, Citrix Gateway
Unauthenticated attackers can cause temporary disruption of management interfaces and APIs in Citrix ADC when configured as a VPN or AAA virtual server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-22955?
CVE-2021-22955 is a high-severity denial of service vulnerability in Citrix ADC, Citrix Gateway, published on 7 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A unauthenticated denial of service vulnerability exists in Citrix ADC <13.0-83.27, <12.1-63.22 and 11.1-65.23 when configured as a VPN (Gateway) or AAA virtual server could allow an attacker to cause a temporary disruption of the Management GUI, Nitro API, and RPC communication.
Weakness: CWE-400
Which versions are affected by CVE-2021-22955?
It affects 2 products.
Products include Citrix Application Delivery Controller Firmware, Citrix Gateway.
How do I fix CVE-2021-22955?
No fix has been published for CVE-2021-22955 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-22955 being exploited?
There is no known exploitation of CVE-2021-22955 in the wild and no public exploit code.
Other vulnerabilities in Citrix ADC, Citrix Gateway
- CVE-2022-27518 Citrix Application Delivery Controller (ADC) and Gateway Authentication Bypass
- CVE-2019-19781 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Code Execution
- CVE-2020-8193 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Authorization Bypass
- CVE-2020-8195 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Information Disclosure
- CVE-2020-8196 Citrix ADC, Gateway, and SD-WAN WANOP Appliance Information Disclosure
Sources
Also known as GHSA-xwgf-rg8j-2j5x.