CVE-2024-20359: Cisco ASA Software RCE Vulnerability

CVE-2024-20359 Overview

A vulnerability in a legacy capability that allowed for the preloading of VPN clients and plug-ins and that has been available in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary code with root-level privileges. Administrator-level privileges are required to exploit this vulnerability.

Critical Impact
This vulnerability could allow attackers to execute arbitrary code on affected devices, potentially altering system behavior and compromising security.

Affected Products

Cisco Adaptive Security Appliance Software
Cisco Firepower Threat Defense

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Cisco
Not Available - CVE CVE-2024-20359 assigned
Not Available - Cisco releases security patch
2024-04-24 - CVE CVE-2024-20359 published to NVD
2025-10-28 - Last updated in NVD database

Technical Details for CVE-2024-20359

Vulnerability Analysis

This vulnerability arises due to improper validation of files when read from system flash memory. An attacker could exploit it by crafting a file and copying it to the device disk. Upon system reload, the arbitrary code could be executed, leading to potential root-level compromise and system behavior alteration.

Root Cause

Improper validation of file integrity when files are read from the flash memory.

Attack Vector

Local

bash

# Example exploitation code (sanitized)
cp malicious_file /disk0/
reload

Detection Methods for CVE-2024-20359

Indicators of Compromise

Unusual files in /disk0:
Unexpected system reboots
Unauthorized changes in system configuration

Detection Strategies

Utilize file integrity monitoring and alert systems to detect unauthorized file changes within the /disk0: directory. Employ behavioral detection techniques to identify anomalous system behaviors indicative of unauthorized reboots or privilege escalations.

Monitoring Recommendations

Regularly audit system files and review access logs for any unauthorized changes or access attempts. Leverage SentinelOne’s threat intelligence feeds to stay updated on detection signatures correlating to this CVE.

How to Mitigate CVE-2024-20359

Immediate Actions Required

Audit current system configurations and file integrity
Implement file integrity monitoring within the /disk0: directory
Enforce strict file permissions to prevent unauthorized write access

Patch Information

Cisco has advised users to apply the latest security updates available on the vendor's advisory page.

Workarounds

Currently, there are no official workarounds. Users should apply vendor patches as soon as they become available to mitigate potential risks.