← Vulnerability feed

Vulnerability record · CVE-2020-3196 · published 6 May 2020

CVE-2020-3196: Cisco secure firewall threat defense uncontrolled resource consumption vulnerability

Cisco · Secure Firewall Threat Defense

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.

8.6 CVSS 3.1 High EPSS 1.9% · top 20.9% CWE-400 · Uncontrolled resource consumption
8.6CVSS 3.1 base score, v2 5.0
1.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
14Affected product versions listed by NVD
2References
11 Aug 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected products

14 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ssl-vpn-dos-qY7BHpjN Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ssl-vpn-dos-qY7BHpjN Vendor Advisory

Track CVE-2020-3196 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.9CVE-2025-20333Cisco ASA and FTD VPN web server buffer overflow allows root RCECisco Secure Firewall ASA and FTD Software fail to properly validate user-supplied input in HTTP(S) requests to the VPN web server, causing a classic…KEVEPSS 71%analysed9.1CVE-2023-20269Cisco ASA and FTD remote access VPN AAA separation flawCisco ASA and FTD remote access VPN features fail to properly separate AAA from the HTTPS management and site-to-site VPN features. An attacker can s…KEVEPSS 25%analysed8.8CVE-2016-6366Cisco ASA SNMP buffer overflow allows remote code executionCisco ASA, PIX and FWSM software through 9.4.2.3 contains a classic buffer overflow (CWE-120) reachable through crafted IPv4 SNMP packets. A remote a…KEVEPSS 88%analysed8.6CVE-2026-20349Cisco ASA and FTD SSL VPN HTTP request handling denial of serviceCisco Secure Firewall ASA and FTD software fail to properly check errors when processing HTTP requests in the Remote Access SSL VPN service. An unaut…KEVEPSS 1.0%analysed8.6CVE-2025-20362Cisco Secure Firewall ASA/FTD VPN web server missing authorizationThe VPN web server in Cisco Secure Firewall ASA and FTD software fails to properly validate user-supplied input in HTTP(S) requests, allowing access …KEVEPSS 87%analysed8.6CVE-2024-20353Cisco ASA and FTD web server HTTP header parsing DoSCisco ASA and FTD management and VPN web servers fail to fully check errors when parsing an HTTP header, so a crafted request can crash and reload th…KEVEPSS 71%analysed7.8CVE-2016-6367Cisco ASA CLI command injection privilege escalationCisco ASA Software before 8.4(1) on ASA 5500, ASA 5500-X, PIX, and FWSM devices mishandles invalid CLI commands, allowing command injection (CWE-77).…KEVEPSS 23%analysed7.5CVE-2020-3452Cisco ASA and FTD web services path traversal file readCisco ASA and FTD web services fail to validate URL input, allowing directory traversal sequences in HTTP requests to read files inside the web servi…KEVEPSS 100%analysed

Source: NIST National Vulnerability Database (record CVE-2020-3196), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.