Firepower Threat Defense
CVE-2020-3585
LOW
Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Lifecycle Timeline
1DescriptionNVD
A vulnerability in the TLS handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 1000 Series firewalls could allow an unauthenticated, remote attacker to gain access to sensitive information. The vulnerability is due to improper implementation of countermeasures against the Bleichenbacher attack for cipher suites that rely on RSA for key exchange. An attacker could exploit this vulnerability by sending crafted TLS messages to the device, which would act as an oracle and allow the attacker to carry out a chosen-ciphertext attack. A successful exploit could allow the attacker to perform cryptanalytic operations that may allow decryption of previously captured TLS sessions to the affected device. To exploit this vulnerability, an attacker must be able to perform both of the following actions: Capture TLS traffic that is in transit between clients and the affected device Actively establish a considerable number of TLS connections to the affected device
AnalysisAI
A vulnerability in the TLS handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 1000 Series firewalls could allow an. Rated low severity (CVSS 3.7), this vulnerability is remotely exploitable, no authentication required.
Technical ContextAI
This vulnerability is classified under CWE-203. A vulnerability in the TLS handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 1000 Series firewalls could allow an unauthenticated, remote attacker to gain access to sensitive information. The vulnerability is due to improper implementation of countermeasures against the Bleichenbacher attack for cipher suites that rely on RSA for key exchange. An attacker could exploit this vulnerability by sending crafted TLS messages to the device, which would act as an oracle and allow the attacker to carry out a chosen-ciphertext attack. A successful exploit could allow the attacker to perform cryptanalytic operations that may allow decryption of previously captured TLS sessions to the affected device. To exploit this vulnerability, an attacker must be able to perform both of the following actions: Capture TLS traffic that is in transit between clients and the affected device Actively establish a considerable number of TLS connections to the affected device Affected products include: Cisco Firepower Threat Defense, Cisco Adaptive Security Appliance Software.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
More in Firepower Threat Defense
View allUpdate: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Softwar
A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Softw
A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Th
A vulnerability in the web services interface for remote access VPN features of Cisco Adaptive Security Appliance (ASA)
A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Th
A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remo
Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Fir
A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower
Multiple vulnerabilities in the multi-instance feature of Cisco Firepower Threat Defense (FTD) Software could allow an a
A vulnerability in the Remote Access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower
A vulnerability in the TLS cryptography functionality of Cisco Adaptive Security Appliance (ASA) Software and Cisco Fire
A vulnerability in the SSL VPN feature for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat D
Same weakness CWE-203 – Observable Discrepancy
View allSame technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today