CVE-2022-20960 Denial of service in Cisco Secure Email
Unauthenticated remote attackers can cause a denial of service on Cisco Email Security Appliances by exhausting resources with concurrent TLS connections.
- 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-2022-20960?
CVE-2022-20960 is a high-severity denial of service vulnerability in Cisco Email Security Appliance, published on 3 Nov 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain TLS connections that are processed by an affected device. An attacker could exploit this vulnerability by establishing a large number of concurrent TLS connections to an affected device. A successful exploit could allow the attacker to cause the device to drop new TLS email messages that come from the associated email servers. Exploitation of this vulnerability does not cause the affected device to unexpectedly reload. The device will recover autonomously within a few hours of when the attack is halted or mitigated.
Which versions are affected by CVE-2022-20960?
It affects 1 product.
Products include Cisco Email Security Appliance.
How do I fix CVE-2022-20960?
No fix has been published for CVE-2022-20960 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-2022-20960 being exploited?
There is no known exploitation of CVE-2022-20960 in the wild and no public exploit code.
Other vulnerabilities in Cisco Email Security Appliance
- CVE-2022-20798 Cisco Email Security Appliance and Cisco Secure Email and Web Manager External Authentication Bypass Vulnerability
- CVE-2015-6291 Denial of service in n/a
- CVE-2022-20664 Cisco Email Security Appliance and Cisco Secure Email and Web Manager Information Disclosure Vulnerability
- CVE-2018-0419 Security feature bypass in Email Security Appliance (ESA)
- CVE-2016-1480 Security feature bypass in Cisco AsyncOS through WSA10.0.0-000
Sources
Also known as GHSA-m7jq-xvr4-f7xc.