CVE-2021-1566: Cisco Email Security Appliance and Cisco Web Security Appliance Certificate Validation Vulnerability
First published: Wed Jun 16 2021(Updated: )
A vulnerability in the Cisco Advanced Malware Protection (AMP) for Endpoints integration of Cisco AsyncOS for Cisco Email Security Appliance (ESA) and Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to intercept traffic between an affected device and the AMP servers. This vulnerability is due to improper certificate validation when an affected device establishes TLS connections. A man-in-the-middle attacker could exploit this vulnerability by sending a crafted TLS packet to an affected device. A successful exploit could allow the attacker to spoof a trusted host and then extract sensitive information or alter certain API requests.
Credit: ykramarz@cisco.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| All of | ||
| Cisco Email Security Appliance | ||
| Cisco AsyncOS | <12.5.3-035 | |
| All of | ||
| Cisco Email Security Appliance | ||
| Cisco AsyncOS | >=13.0<13.0.0-030 | |
| All of | ||
| Cisco Email Security Appliance | ||
| Cisco AsyncOS | >=13.5<13.5.3-010 | |
| All of | ||
| Cisco Web Security Appliance | ||
| Cisco AsyncOS | <11.8.3-021 | |
| All of | ||
| Cisco Web Security Appliance | ||
| Cisco AsyncOS | >=12.0.0<12.0.3-005 | |
| All of | ||
| Cisco Web Security Appliance | ||
| Cisco AsyncOS | >=12.5.0<12.5.1-043 |
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Reference Links
Frequently Asked Questions
What is the vulnerability ID?
The vulnerability ID is CVE-2021-1566.
What is the severity of CVE-2021-1566?
The severity of CVE-2021-1566 is high.
Which software is affected by CVE-2021-1566?
Cisco Email Security Appliance and Cisco Web Security Appliance with specific versions of Cisco AsyncOS are affected by CVE-2021-1566.
How can an attacker exploit CVE-2021-1566?
An unauthenticated, remote attacker can exploit CVE-2021-1566 to intercept traffic between an affected device and the AMP server.
How can I fix CVE-2021-1566?
Upgrade Cisco AsyncOS to a version that is not affected by CVE-2021-1566.
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- collector/mitre-cve
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- vendor/cisco
- canonical/cisco email security appliance
- canonical/cisco asyncos
- version/cisco asyncos/13.0
- version/cisco asyncos/13.5
- canonical/cisco web security appliance
- version/cisco asyncos/12.0.0
- version/cisco asyncos/12.5.0