Actively exploited in the wild

Cisco ASA and FTD Read-Only Path Traversal Vulnerability

Cisco - Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) · Listed in the CISA KEV since 2021-11-03. This indicates confirmed attacks in production environments.

Required action: Apply updates per vendor instructions.

CVE-2020-3452

HighCVSS 7.5KEV

Published: 22/07/2020(UTC)Updated: 11/08/2026(UTC)Translated: 12/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Very high risk

99.99%

100th percentile - higher than 100% of all known CVEs

Summary

A vulnerability in the web services interface of Cisco ASA and FTD Software allows an unauthenticated, remote attacker to perform directory traversal attacks and read sensitive files. The issue is due to lack of proper input validation of URLs in HTTP requests. A successful exploit allows viewing arbitrary files within the web services file system when WebVPN or AnyConnect features are enabled.

Risk Assessment

Risk of exposure of sensitive files in the web services file system, which could aid further attacks.

Recommendation

Apply Cisco updates, or if not possible, disable or restrict access to WebVPN and AnyConnect features.

Original NVD description (English source)

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 conduct directory traversal attacks and read sensitive files on a targeted system. The vulnerability is due to a lack of proper input validation of URLs in HTTP requests processed by an affected device. An attacker could exploit this vulnerability by sending a crafted HTTP request containing directory traversal character sequences to an affected device. A successful exploit could allow the attacker to view arbitrary files within the web services file system on the targeted device. The web services file system is enabled when the affected device is configured with either WebVPN or AnyConnect features. This vulnerability cannot be used to obtain access to ASA or FTD system files or underlying operating system (OS) files.