CVE-2020-3585

What it is

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

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

1.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2020-10-21 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-11 19:42 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.3% in the next 30 days (EPSS).
• Severity: 5.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2020-10-21 19:15 UTC

Last modified

2026-08-11 19:42 UTC

Exploit probability

1.3% · EPSS, next 30 days

Weakness

CWE-203

Record status

Modified

Affected

• Cisco Secure Firewall Threat Defense < 6.4.0.10
• Cisco Firepower Threat Defense < 6.5.0.5
• Cisco Firepower Threat Defense < 6.6.1
• Cisco Adaptive Security Appliance Software < 9.13.1.13
• Cisco Adaptive Security Appliance Software < 9.14.1.30

Attack profile CVSS 3.1 · 5.3

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2020-3585.md and follow it. Check whether this project is affected by CVE-2020-3585. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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