Cisco ASA Improper Neutralization of Special Elements in Output Used by a Downstream Component (CVE-2020-3561)

medium Tenable OT Security Plugin ID 506186

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability in the Clientless SSL VPN (WebVPN) of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to inject arbitrary HTTP headers in the responses of the affected system.
The vulnerability is due to improper input sanitization. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to conduct a CRLF injection attack, adding arbitrary HTTP headers in the responses of the system and redirecting the user to arbitrary websites.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: Medium

ID: 506186

File Name: tenable_ot_cisco_CVE-2020-3561.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 10/6/2026

Updated: 10/6/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS Score Source: CVE-2020-3561

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Vulnerability Information

CPE: cpe:/o:cisco:adaptive_security_appliance_software:9

Required KB Items: Tenable.ot/Cisco

Patch Publication Date: 10/21/2020

Vulnerability Publication Date: 10/21/2020

Reference Information

CVE: CVE-2020-3561

CWE: 74, 93

Detections

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