Background exploitation KEV catalog Ransomware No authentication
CVE-2020-3259

Cisco ASA and FTD Information Disclosure Vulnerability

A vulnerability 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 retrieve memory contents on an affected…

CheckOps priority index
8.1/10 Patch within 24 h
Severity7.5
Probability7.1
Exploitation5/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 71.5% higher than 99.4% of CVEs
CVSS 3.0 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 992 days 15 Feb 2024
CISA due date 07 Mar 2024 for US federal agencies

Exploitation probability EPSS · FIRST

05010026 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 5 / 5

  • KEV catalog (CISA)15 Feb 2024
  • Exploited in EUVD (ENISA)15 Feb 2024
  • Used by ransomwareyes
  • EPSS above 10 %71.5%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

A vulnerability 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 retrieve memory contents on an affected device, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.

Affected products

Cisco Adaptive Security Appliance (ASA) SoftwareAdaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 71.8%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-76418Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
    5.3 · Rising fast
  • CVE-2026-76519Cisco Secure Email Gateway Relative Path Traversal Vulnerability
    5.8 · Rising fast
  • CVE-2026-76504Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
    7.5 · Actively exploited
  • CVE-2026-76460Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
    8.7 · Actively exploited
  • CVE-2026-76461Cisco Secure Email Gateway SQL Injection Vulnerability
    7.2 · Actively exploited
  • CVE-2026-20079Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
    9.1 · Actively exploited

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities