CVE-2023-20215 Security feature bypass in Cisco Secure Web Appliance
Unauthenticated attackers can bypass web filtering rules on Cisco Secure Web Appliances by exploiting improper detection of encoded malicious traffic.
- 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-2023-20215?
CVE-2023-20215 is a medium-severity vulnerability in Cisco Asyncos, published on 3 Aug 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in the scanning engines of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to bypass a configured rule, allowing traffic onto a network that should have been blocked. This vulnerability is due to improper detection of malicious traffic when the traffic is encoded with a specific content format. An attacker could exploit this vulnerability by using an affected device to connect to a malicious server and receiving crafted HTTP responses. A successful exploit could allow the attacker to bypass an explicit block rule and receive traffic that should have been rejected by the device.
Weakness: CWE-202
Which versions are affected by CVE-2023-20215?
It affects 1 product.
Products include Cisco Asyncos.
How do I fix CVE-2023-20215?
No fix has been published for CVE-2023-20215 yet. Limit exposure of the affected software until one is available.
Is CVE-2023-20215 being exploited?
There is no known exploitation of CVE-2023-20215 in the wild and no public exploit code.
Other vulnerabilities in Cisco Asyncos
- CVE-2025-20393 Cisco Multiple Products Improper Input Validation
- CVE-2026-76519 Cisco Secure Email Gateway Relative Path Traversal
- CVE-2026-76461 Cisco Secure Email Gateway SQL Injection
- CVE-2024-20435 Command injection in Cisco Secure Web Appliance
- CVE-2019-15956 Cisco Web Security Appliance Unauthorized Device Reset Vulnerability
Sources
Also known as GHSA-4qcp-whvm-5mwc.