Cisco ASA Unrestricted Upload of File with Dangerous Type (CVE-2020-3436)

high Tenable OT Security Plugin ID 506073

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to upload arbitrary-sized files to specific folders on an affected device, which could lead to an unexpected device reload. The vulnerability exists because the affected software does not efficiently handle the writing of large files to specific folders on the local file system. An attacker could exploit this vulnerability by uploading files to those specific folders. A successful exploit could allow the attacker to write a file that triggers a watchdog timeout, which would cause the device to unexpectedly reload, causing a denial of service (DoS) condition.

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Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 506073

File Name: tenable_ot_cisco_CVE-2020-3436.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 10/5/2026

Updated: 10/5/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.3

Percentile: 50.87

CVSS v2

Risk Factor: High

Base Score: 7.8

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

CVSS Score Source: CVE-2020-3436

CVSS v3

Risk Factor: High

Base Score: 8.6

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

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-2020-3436

CWE: 434

Detections

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