Vulnerability Database

326,214

Total vulnerabilities in the database

CVE-2020-3196

A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust memory resources on the affected device, leading to a denial of service (DoS) condition. The vulnerability is due to improper resource management for inbound SSL/TLS connections. An attacker could exploit this vulnerability by establishing multiple SSL/TLS connections with specific conditions to the affected device. A successful exploit could allow the attacker to exhaust the memory on the affected device, causing the device to stop accepting new SSL/TLS connections and resulting in a DoS condition for services on the device that process SSL/TLS traffic. Manual intervention is required to recover an affected device.

  • Published: May 6, 2020
  • Updated: Nov 16, 2025
  • CVE: CVE-2020-3196
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 8.6
  • AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS v2:

  • Severity: Medium
  • Score: 5
  • AV:N/AC:L/Au:N/C:N/I:N/A:P

CWEs:

Software From Fixed in
cisco / firepower_threat_defense 6.5.0 6.5.0.5
cisco / firepower_threat_defense 6.4.0 6.4.0.9
cisco / firepower_threat_defense 6.3.0 6.3.0.6
cisco / firepower_threat_defense 6.2.3 6.2.3.16
cisco / asa_5505_firmware 9.4(4) 9.4(4).x
cisco / asa_5505_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5505_firmware 100.13(0) 100.13(0).x
cisco / asa_5510_firmware 9.4(4) 9.4(4).x
cisco / asa_5510_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5510_firmware 100.13(0) 100.13(0).x
cisco / asa_5512-x_firmware 9.4(4) 9.4(4).x
cisco / asa_5512-x_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5512-x_firmware 100.13(0) 100.13(0).x
cisco / asa_5515-x_firmware 9.4(4) 9.4(4).x
cisco / asa_5515-x_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5515-x_firmware 100.13(0) 100.13(0).x
cisco / asa_5520_firmware 9.4(4) 9.4(4).x
cisco / asa_5520_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5520_firmware 100.13(0) 100.13(0).x
cisco / asa_5525-x_firmware 9.4(4) 9.4(4).x
cisco / asa_5525-x_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5525-x_firmware 100.13(0) 100.13(0).x
cisco / asa_5540_firmware 9.4(4) 9.4(4).x
cisco / asa_5540_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5540_firmware 100.13(0) 100.13(0).x
cisco / asa_5545-x_firmware 9.4(4) 9.4(4).x
cisco / asa_5545-x_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5545-x_firmware 100.13(0) 100.13(0).x
cisco / asa_5550_firmware 9.4(4) 9.4(4).x
cisco / asa_5550_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5550_firmware 100.13(0) 100.13(0).x
cisco / asa_5555-x_firmware 9.4(4) 9.4(4).x
cisco / asa_5555-x_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5555-x_firmware 100.13(0) 100.13(0).x
cisco / asa_5580_firmware 9.4(4) 9.4(4).x
cisco / asa_5580_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5580_firmware 100.13(0) 100.13(0).x
cisco / asa_5585-x_firmware 9.4(4) 9.4(4).x
cisco / asa_5585-x_firmware 9.8(4.18) 9.8(4.18).x
cisco / asa_5585-x_firmware 100.13(0) 100.13(0).x
cisco / adaptive_security_appliance_software 9.8 9.8.4.20
cisco / adaptive_security_appliance_software 9.9 9.9.2.66
cisco / adaptive_security_appliance_software 9.13 9.13.1.7
cisco / adaptive_security_appliance_software 9.10 9.10.1.37
cisco / adaptive_security_appliance_software 9.12 9.12.3.2
cisco / adaptive_security_appliance_software 9.6 9.6.4.40

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.