CVE-2021-1566: cisco asyncos
Vulnerability summary
CVE-2021-1566 is a high (CVSS 7.4) vulnerability in cisco asyncos. EPSS estimates a 0.67% chance of exploitation in the next 30 days, higher than 51% of scored vulnerabilities.
Timeline
- 16-06-2021PublishedVulnerability first disclosed.
- 07-11-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST7.4HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS trend
Probability
0.67%
Chance of exploitation in the next 30 days
Percentile
51%
Versus all other CVEs
30-day change
0.00 pp
From 0.67% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Cisco4 products
- asyncos< 12.5.3-035 | ≥ 13.0, < 13.0.0-030 | ≥ 13.5, < 13.5.3-010 | < 11.8.3-021 | ≥ 12.0.0, < 12.0.3-005 | ≥ 12.5.0, < 12.5.1-043
- cisco web security appliance (wsa)n/a
- email_security_appliance_firmwarena
- web_security_appliancena
1 vendor · 4 products
References
1 links- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-wsa-cert-vali-n8L97RWVendor AdvisoryX Refsource CISCO