What’s Vulnerable › Vulnerabilities
CVE-2020-3548: Cisco Email Security Appliance Denial Of Service Vulnerability
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.8% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2024-11-18 · updated 2026-06-17
- Weakness: CWE-407
Description
A vulnerability in the Transport Layer Security (TLS) protocol implementation of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient processing of incoming TLS traffic. An attacker could exploit this vulnerability by sending a series of crafted TLS packets to an affected device. A successful exploit could allow the attacker to trigger a prolonged state of high CPU utilization. The affected device would still be operative, but response time and overall performance may be degraded.There are no workarounds that address this vulnerability.
Affected products
- Cisco Email Security Appliance (ESA): through 13.5.1-277
References
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