Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03 · Ransomware

CVE-2020-3580

MEDIUM

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,…

Published
Oct 21, 2020
Updated
Jun 17, 2026
Affected
0 pkgs
Patched
None yet
Exploits
5 known

EPSS Exploitation Probability

via FIRST.org ↗
85.6%probability of exploitation in next 30 days
Very High Risk100th percentile+0.14%
83.1%87.3%91.5%95.7%91.4%85.6%Jan 26May 26Jul 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

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.

Affected Products

2 products · 9 configurations
OS
adaptive security appliance softwarecisco
≥ 9.15 && < 9.15.1.15
range
OS
firepower threat defensecisco
≥ 6.7.0 && < 6.7.0.2
range
Exploits & PoCs
5

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every cisco adaptive security appliance software deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Fix

    Apply the cisco adaptive security appliance software security patch or hotfix for CVE-2020-3580 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2020-3580 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2020-3580. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 at
O3 Security · Runtime Protection

Is CVE-2020-3580 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2020-3580 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

CVE-2020-3580: Adaptive Security Appliance Software Cross-site… | O3 Security