CVE-2020-3585: cisco adaptive_security_appliance_software Observable Discrepancy

Vulnerability summary

CVE-2020-3585 is a medium (CVSS 5.3) Observable Discrepancy vulnerability in cisco adaptive_security_appliance_software. EPSS estimates a 1.26% chance of exploitation in the next 30 days, higher than 69.2% of scored vulnerabilities.

Timeline

1. 21-10-2020
   PublishedVulnerability first disclosed.
2. 13-11-2024
   Last modifiedVulnerability information updated.

Description

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

• CWE-203Observable DiscrepancyThe product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.