CVE-2020-3259 HIGH

CVE-2020-3259: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Information Disclosure Vulnerability

Vendor Cisco
Product Cisco Adaptive Security Appliance (ASA) Software
Weakness CWE-200 · Info exposure
KEV Status Known Exploited
Ransomware Used in campaigns
Published May 6, 2020
Last update October 21, 2025

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to retrieve memory contents on an affected device, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.

CISA mandated remediation

02CISA Required Action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Key dates

03Disclosure timeline

May 6, 2020 CVE published
October 21, 2025 Record updated