How to Fix CVE-2024-20419 - A Critical Password Change Vulnerability in On-Prem Cisco SSM?

Cisco recently disclosed a critical vulnerability affecting its Smart Software Manager On-Prem (SSM On-Prem) product. The flaw, tracked as CVE-2024-20419, allows an unauthenticated remote attacker to change the password of any user account, including those with administrative privileges. With a maximum CVSS score of 10.0, this vulnerability poses a severe risk to organizations using affected versions of Cisco SSM On-Prem.

The vulnerability stems from improper implementation of the password change process in the authentication system. By exploiting this flaw, attackers can bypass authentication mechanisms and gain unauthorized access to the web UI or API with the privileges of the compromised user. This could lead to complete system compromise, data breaches, and further network infiltration.

Cisco has released software updates to address this critical issue. Given the severity and potential impact of CVE-2024-20419, it is crucial for organizations using Cisco SSM On-Prem to understand the vulnerability and take immediate action to protect their systems.

In this article, we will examine the details of CVE-2024-20419, its impact on Cisco SSM On-Prem deployments, and provide step-by-step guidance on how to mitigate this vulnerability. We'll cover affected products, detection methods, patching procedures, and additional security measures to enhance the overall security of your Cisco SSM On-Prem environment.

Key points about this vulnerability:

A Short Introduction to Cisco SSM On-Prem

Cisco Smart Software Manager On-Prem (SSM On-Prem) is a component of Cisco's software licensing infrastructure that allows organizations to manage Cisco software licenses and product activations locally within their own network. This on-premises solution is particularly useful for enterprises that have strict security policies or limited internet connectivity.

Key features of Cisco SSM On-Prem include:

It's important to note that in versions prior to Release 7.0, this product was known as Cisco Smart Software Manager Satellite (SSM Satellite). From Release 7.0 onwards, it has been rebranded as Cisco SSM On-Prem. Both names refer to the same product line, which is critical for identifying affected systems across different version ranges.

Cisco SSM On-Prem plays a vital role in many enterprise environments, making the security of this platform paramount for maintaining the integrity of an organization's software licensing and management infrastructure.

Summary of the Vulnerability

Here's a summary of the critical vulnerability affecting Cisco Smart Software Manager On-Prem:

CVE-2024-20419 is a critical authentication bypass vulnerability in the Cisco Smart Software Manager On-Prem (SSM On-Prem) that could allow an unauthenticated, remote attacker to change the password of any user, including administrative users. This vulnerability stems from improper implementation of the password change process in the authentication system.

The root cause of this vulnerability lies in the endpoint responsible for generating One-Time Passwords (OTPs) for password resets:

/backend/reset_password/generate_code

When a POST request is sent to this endpoint, it is intended to trigger the generation of an OTP for password reset authentication. However, in vulnerable versions of the application, the response to this request not only confirms that the OTP code has been sent but also erroneously includes the authorization token (auth_token).

This authorization token should only be issued after successful verification of the OTP code. By prematurely exposing the token in the OTP generation response, the application inadvertently grants an attacker the means to bypass the OTP verification step entirely. With the token in hand, an attacker can directly authorize themselves to change the password of the targeted account without needing to verify the OTP.

Technical Details

The CVE-2024-20419 vulnerability in Cisco Smart Software Manager On-Prem (SSM On-Prem) stems from a critical flaw in the authentication system, specifically in the password change process. The technical details of this vulnerability reveal how the improper implementation of authorization tokens related to OTP generation creates a significant security risk.

Vulnerable Component

The vulnerability is located in the web-based user interface (web UI) API of Cisco SSM On-Prem, specifically in the endpoint responsible for generating One-Time Passwords (OTPs) for password resets:

/backend/reset_password/generate_code

This endpoint is designed to initiate the password reset process by generating an OTP that should be verified before allowing a password change.

Exploitation Process

The exploitation of CVE-2024-20419 involves the following steps:

Image Source: https://www.0xpolar.com/blog/CVE-2024-20419

1. An attacker sends a POST request to the vulnerable endpoint /backend/reset_password/generate_code.

2. The request includes the target user's UID (username or email).

3. The server generates an OTP for the password reset process.

4. Instead of only confirming OTP generation, the server response erroneously includes an auth_token.

5. This auth_token is prematurely issued, bypassing the intended OTP verification step.

6. The attacker can then use this auth_token to directly change the password of the targeted account.

Proof of Concept

A proof of concept (PoC) exploit script has been made publicly available, demonstrating the ease with which this vulnerability can be exploited. The key components of the PoC include:

1. Sending a GET request to obtain necessary tokens (XSRF token and session cookie).

2. Posting to the vulnerable endpoint to generate the OTP and retrieve the auth_token.

3. Using the obtained auth_token to reset the password without verifying the OTP.

Root Cause Analysis

The root cause of this vulnerability appears to be a logic flaw in the authentication process:

1. The application generates an auth_token at the OTP creation stage instead of after OTP verification.

2. This auth_token is then exposed in the API response, allowing it to be captured by an attacker.

3. The password reset functionality accepts this auth_token without verifying that the OTP step has been completed.

This implementation error effectively bypasses the two-step verification process (OTP generation followed by OTP verification) that was intended to secure the password reset functionality.

Understanding these technical details is crucial for security teams to assess the risk to their environments and to verify the effectiveness of patches or mitigations implemented to address this vulnerability.

Products Affected by the Vulnerability

The CVE-2024-20419 vulnerability affects specific versions of Cisco Smart Software Manager On-Prem (SSM On-Prem) and its predecessor, Cisco Smart Software Manager Satellite (SSM Satellite). Here's a detailed breakdown of the affected products and versions:

Important Notes:

Products Confirmed Not Vulnerable

Cisco has explicitly confirmed that the following products are not affected by CVE-2024-20419:

Exemptions

While not explicitly listed as exemptions, it's worth noting:

Version Check

To determine if your deployment is vulnerable:

If you're running version 8-202206 or earlier of SSM On-Prem, or any version of SSM Satellite, your system is vulnerable and requires immediate attention.

How to Check if Your Product is Vulnerable?

Identifying whether your Cisco Smart Software Manager On-Prem (SSM On-Prem) deployment is vulnerable to CVE-2024-20419 is crucial for proper risk assessment and mitigation. Here are several methods to check for vulnerability:

1. Version Check

The simplest way to determine vulnerability is by checking your product version:

2. Command Line Interface (CLI) Check

For administrators with CLI access:

show version

Look for the version number in the output and compare it to the vulnerable versions list.

3. Check for Vulnerable Endpoint

Test for the presence of the vulnerable endpoint:

1. Attempt to access the following URL (replace <your-ssm-onprem-url> with your actual SSM On-Prem URL):

2. If this endpoint is accessible and returns a response, your system may be vulnerable.

4. Vulnerability Scanners

Many popular vulnerability scanners have added checks for CVE-2024-20419. Update your vulnerability scanner to the latest version and run a scan against your SSM On-Prem instances. Look for any findings related to CVE-2024-20419.

Ways to Check the Exploitation Attempt

The best way to identify the exploitation attempts is to verify the logs and events in different security solutions.

1. Web Application Firewall (WAF) Logs

If you have a WAF in front of your SSM On-Prem instance, configure it to look for suspicious requests to the vulnerable endpoint:

/backend/reset_password/generate_code

Analyze logs for any unusual activity or attempted exploits.

2. SIEM and Log Analysis

Configure your SIEM solution to alert on potential exploitation attempts:

3. Network Traffic Analysis

Use network monitoring tools to look for suspicious traffic patterns:

1. Unexpected POST requests to /backend/reset_password/generate_code.

2. Unusual data transfers from your SSM On-Prem instance.

How to Fix the Vulnerability?

Addressing CVE-2024-20419 in Cisco Smart Software Manager On-Prem (SSM On-Prem) requires prompt action. Cisco has released software updates to fix this critical vulnerability. Here are the steps to mitigate and resolve the issue:

1. Apply the Patch

The most effective way to address CVE-2024-20419 is to upgrade to a patched version of Cisco SSM On-Prem:

Follow these steps to upgrade:

2. Workarounds

Cisco has not provided any official workarounds for this vulnerability. The only complete solution is to upgrade to a patched version.

3. Temporary Mitigation Measures

If immediate patching is not possible, consider these temporary mitigation steps:

2. Enhance Network Segmentation:

3. Disable Web UI (if possible):

4. Implement Strong Authentication:

5. Enhanced Monitoring:

By implementing these fixes, mitigations, and best practices, you can significantly reduce the risk posed by CVE-2024-20419 and improve the overall security posture of your Cisco Smart Software Manager On-Prem deployment.

Conclusion

CVE-2024-20419 represents a critical security risk for organizations using Cisco Smart Software Manager On-Prem. The ability for an unauthenticated attacker to change any user's password, including those of administrators, could lead to severe breaches and operational disruptions.

Immediate action is required to mitigate this vulnerability:

We hope this post helps explores the details of CVE-2024-20419, its potential impact, and provide guidance on how to protect your Cisco SSM On-Prem deployment from this critical vulnerability. Thanks for reading this post. Please share this post and help secure the digital world.Visit our website thesecmaster.com, and our social media page

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