CVE-2023-20057 Security feature bypass in Cisco Email Security Appliance (ESA)
Unauthenticated attackers can bypass URL reputation filters on Cisco Email Security Appliances by crafting specific URLs, allowing malicious links to pass through.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2023-20057?
CVE-2023-20057 is a vulnerability in Cisco Asyncos, published on 19 Jan 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A vulnerability in the URL filtering mechanism of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the URL reputation filters on an affected device. This vulnerability is due to improper processing of URLs. An attacker could exploit this vulnerability by crafting a URL in a particular way. A successful exploit could allow the attacker to bypass the URL reputation filters that are configured for an affected device, which could allow malicious URLs to pass through the device.
Which versions are affected by CVE-2023-20057?
It affects 1 product.
Products include Cisco Asyncos.
How do I fix CVE-2023-20057?
No fix has been published for CVE-2023-20057 yet. Limit exposure of the affected software until one is available.
Is CVE-2023-20057 being exploited?
There is no known exploitation of CVE-2023-20057 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-72vc-2hjp-vr3j.