CVE-2020-3259: Cisco ASA and FTD Information Disclosure Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: yes — in CISA KEV since 2024-02-15
EPSS: 71.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-05-06 · updated 2026-08-12
Weakness: CWE-200

Description

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.

Affected products

Cisco ASA Software: from 9.8 before 9.8.4.20; from 9.9 before 9.9.2.67; from 9.10 before 9.10.1.40; from 9.12 before 9.12.3.9; from 9.13 before 9.13.1.10 — fixed in 9.10.1.40, 9.12.3.9, 9.13.1.10, 9.8.4.20, 9.9.2.67
Cisco Firepower Threat Defense Software: from 6.2.3 before 6.2.3.16; from 6.3.0 before 6.3.0.6; from 6.4.0 before 6.4.0.9; from 6.5.0 before 6.5.0.5 — fixed in 6.2.3.16, 6.3.0.6, 6.4.0.9, 6.5.0.5

How to fix

Upgrade to a fixed version: Cisco ASA Software 9.10.1.40, 9.12.3.9, 9.13.1.10, 9.8.4.20; Cisco Firepower Threat Defense Software 6.2.3.16, 6.3.0.6, 6.4.0.9, 6.5.0.5. Check the vendor advisory for mitigations.

References

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