CVE-2020-3580 — Adaptive Security Appliance (ASA) Software

What is CVE-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 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.

The record classifies CVE-2020-3580 under weakness class CWE-79. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 2193 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 6.1 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (FIRST): 85.5% probability of exploitation in the next 30 days, higher than 99.7% of all scored CVEs
CISA KEV: Listed since 2021-11-03, federal remediation deadline 2022-05-03 — used in known ransomware campaigns
Threadlinqs priority: 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
Published: 2020-10-21, last modified 2025-10-21

Is CVE-2020-3580 being exploited?

CISA added CVE-2020-3580 to the Known Exploited Vulnerabilities catalog on 2021-11-03, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2022-05-03 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. Weaponised exploit code for CVE-2020-3580 is publicly available. 5 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2020/CVE-2020-3580.yaml). It currently carries a trending score of 50 in the Threadlinqs vulnerability feed.

Affected products and versions

Cisco: Adaptive Security Appliance (ASA) Software

How to fix CVE-2020-3580

Because CVE-2020-3580 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2022-05-03. No vendor patch reference has been recorded for CVE-2020-3580 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2020-3580

1 tracked threat in the Threadlinqs corpus references CVE-2020-3580, either in the campaign’s CVE list or as an indicator on the campaign record.

Healthcare Sector Ransomware Targeting and Expanding Attack Surface (Qilin, Akira, DragonForce, LockBit, The Gentlemen) — HIGH · 2026-10-09

Sources

Enriched from CVE.org, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on 2026-10-10.

Vendor advisory and patch

tools.cisco.com — vendor advisory

CVE-2020-3580 — Cisco Adaptive Security Appliance (ASA) Software