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Vulnerabilities

Vulnerability · CVE-2020-3580

Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerability

Published Oct 21, 2020 · catalog updated Aug 11, 2026 · Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)

Patch now

CVE-2020-3580 is in the CISA known-exploited catalog, due May 3, 2022. Confirm Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Medium6.1
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
85.58%
Remediation
Remediation guidance
Affected products
cpe cisco/adaptive security appliance software · cpe cisco/secure firewall threat defense · vendor Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)

Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web services interface of an affected device. The vulnerabilities are due to insufficient validation of user-supplied input by the web services interface of an affected device. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive, browser-based information. Note: These vulnerabilities affect only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe cisco/adaptive security appliance softwareversion unspecified
  • cpe cisco/secure firewall threat defenseversion unspecified
  • vendor Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)version unspecified

How to fix CVE-2020-3580

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2020-3580 is in the CISA known-exploited catalog, due May 3, 2022. Confirm Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply updates per vendor instructions.

What should an analyst verify?

CWE-79: Cross-site Scripting (XSS). EPSS 85.58%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Cisco security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2020 · Catalog

    Detected

    Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web services interface of an affected device. The vulnerabilities are due to insufficient validation of user-supplied input by

  2. Nov 3, 2021 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. May 3, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Aug 11, 2026 · Catalog

    Updated

    Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web services interface of an affected device. The vulnerabilities are due to insufficient validation of user-supplied input by

Sources

  • CISA KEVConfirmed exploitationCVE-2020-3580

    Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an insufficient input validation vulnerability for user-supplied input by the web services interface. Successful exploitation could allow an attacker to perform cross-site scripting (XSS) in the context of the interface or access sensitive browser-based information.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2020-3580

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2020-3580

    30-day exploitation probability 85.6%

    first.org
  • NIST NVDVulnerability recordCVE-2020-3580

    Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web ser

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2020-3580

    Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an insufficient input validation vulnerability for user-supplied input by the web services interface. Successful exploitation could allow an attacker to perform cross-site scripting (XSS) in the co

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.