CVE-2019-1873

What it is

A vulnerability in the cryptographic driver for Cisco Adaptive Security Appliance Software (ASA) and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reboot unexpectedly. The vulnerability is due to incomplete input validation of a Secure Sockets Layer (SSL) or Transport Layer Security (TLS) ingress packet header. An attacker could exploit this vulnerability by sending a crafted TLS/SSL packet to an interface on the targeted device. An exploit could allow the attacker to cause the device to reload, which will result in a denial of service (DoS) condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability affects systems configured in routed and transparent firewall mode and in single or multiple context mode. This vulnerability can be triggered by IPv4 and IPv6 traffic. A valid SSL or TLS session is required to exploit this vulnerability.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Exploit odds

2.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2019-07-10 18:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 02:29 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.5% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2019-07-10 18:15 UTC

Last modified

2026-06-17 02:29 UTC

Exploit probability

2.5% · EPSS, next 30 days

Weakness

CWE-400 · Uncontrolled resource consumption

Record status

Modified

Affected

• Cisco Asa 5506-x Firmware 9.6\(4.16\)
• Cisco Asa 5506-x Firmware 9.8\(3.8\)
• Cisco Asa 5506h-x Firmware 9.6\(4.16\)
• Cisco Asa 5506h-x Firmware 9.8\(3.8\)
• Cisco Asa 5506w-x Firmware 9.6\(4.16\)
• Cisco Asa 5506w-x Firmware 9.8\(3.8\)
• Cisco Asa 5508-x Firmware 9.6\(4.16\)
• Cisco Asa 5508-x Firmware 9.8\(3.8\)

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2019-1873.md and follow it. Check whether this project is affected by CVE-2019-1873. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge