CVE-2020-3283: Cisco ASA 5505 Firmware
High severity, CVSS 8.6. EPSS: 2% chance of exploitation in the next 30 days.
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) handler of Cisco Firepower Threat Defense (FTD) Software when running on the Cisco Firepower 1000 Series platform could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. The vulnerability is due to a communication error between internal functions. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause a buffer underrun, which leads to a crash. The crash causes the affected device to reload.
Affected products
- Cisco ASA 5505 Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5510 Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5512-X Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5515-X Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5520 Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5525-X Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5540 Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5545-X Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5550 Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5555-X Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5580 Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco ASA 5585-X Firmware: version 9.12(2.12) only; version 9.13(0.33) only
- Cisco Secure Firewall Threat Defense: from 6.4.0, before 6.4.0.9 (fixed in 6.4.0.9)
Published 2020-05-06. Last modified 2026-08-11.