CVE-2020-3585
MediumCVSS 5.3Exploitation Probability (EPSS)
Elevated risk67th percentile - higher than 67% of all known CVEs
Summary
A vulnerability in the TLS handler of Cisco ASA and FTD Software for Firepower 1000 Series firewalls could allow an unauthenticated, remote attacker to gain access to sensitive information. The issue is due to improper implementation of countermeasures against the Bleichenbacher attack for RSA-based cipher suites. An attacker could send crafted TLS messages, enabling a chosen-ciphertext attack and potential decryption of previously captured TLS sessions.
Risk Assessment
Exposure of sensitive information could lead to confidentiality breaches of data traversing the device, with serious implications for the organization.
Recommendation
It is recommended to update ASA and FTD software to patched versions and limit TLS connections to the device if possible.
Original NVD description (English source)
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