CVE-2019-1873 Cisco ASA and FTD Software Cryptographic TLS and SSL Driver Denial of Service Vulnerability
Remote attackers can cause Cisco ASA and FTD devices to reboot by sending crafted TLS/SSL packets, resulting in a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-1873?
CVE-2019-1873 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance (ASA) Software, published on 10 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2019-1873?
It affects 5 products.
Products include Cisco Asa 5506-X Firmware, Cisco Asa 5506h-X Firmware, Cisco Asa 5506w-X Firmware, Cisco Asa 5508-X Firmware, Cisco Asa 5516-X Firmware.
How do I fix CVE-2019-1873?
No fix has been published for CVE-2019-1873 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2019-1873 being exploited?
There is no known exploitation of CVE-2019-1873 in the wild and no public exploit code.
Sources
Also known as GHSA-q443-v72w-7x2v.