CVE-2020-3452VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2020-3452: Cisco ASA and FTD Read-Only Path Traversal Vulnerability

Affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)Source CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 05/03/2022
EPSS: 100.0% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2020-3452 (opens in a new tab)

Description

CVE-2020-3452 is a high-severity vulnerability in Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) that allows attackers to exploit improper input validation in HTTP request URL processing. By sending crafted HTTP requests with directory traversal sequences, attackers can read arbitrary files on the device's web services file system. This vulnerability has been exploited in the wild.

Summary

Cisco ASA and FTD devices contain an improper input validation vulnerability when processing HTTP request URLs. An attacker can exploit this by sending a crafted HTTP request containing directory traversal character sequences, enabling unauthorized read-only access to arbitrary files within the web services file system on the targeted device. This vulnerability is identified as CVE-2020-3452 and has been observed in active exploitation scenarios.

Impact

Successful exploitation allows an attacker to view arbitrary files on the affected device's web services file system, potentially exposing sensitive configuration or system information. This can lead to information disclosure that may facilitate further attacks or compromise.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is confirmed, restrict network access to the management interface and monitor for suspicious HTTP requests containing directory traversal patterns.

Weaknesses

CWE-20Improper Input Validation (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:27:52 UTC

Weaknesses

References

Related threats