CVE-2023-20238: Critical Vulnerability in Cisco BroadWorks Single Sign-On Implementation

A newly identified vulnerability (CVE-2023-20238) exists in Cisco BroadWorks Application Delivery Platform and Cisco BroadWorks Xtended Services Platform. The vulnerability lies in the Single Sign-On (SSO) implementation. The exploit could potentially result in an unauthenticated remote attacker bypassing the authentication mechanism and forging the necessary credentials to gain unauthorized access to an affected system.

Original References

Cisco Security Advisory (Official): [https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bwx-sso-rlzqCyxF]

National Vulnerability Database (NVD) entry: [https://nvd.nist.gov/vuln/detail/CVE-2023-20238]

Exploit Details

This vulnerability stems from the method used to validate SSO tokens, which allows an attacker to exploit the system by authenticating with forged credentials. A successful exploit enables the attacker to carry out toll fraud or execute commands at the privilege level of the forged account.

If the compromised account is an Administrator account, the attacker could access confidential information, modify customer settings, or alter settings for other users.

To execute this exploit, the attacker requires a valid user ID that is associated with the affected Cisco BroadWorks system.

Proof of Concept (PoC) Code Snippet

While full PoC code is not available, here's a representation of how an attacker might forge credentials:

import base64
import json

def forge_sso_token(user_id, privilege_level):
    fake_payload = {
        "UserId": user_id,
        "PrivilegeLevel": privilege_level,
    }

    # Base64 encode the fake payload
    forged_sso_token = base64.b64encode(json.dumps(fake_payload).encode("utf-8")).decode("utf-8")
    return forged_sso_token

# Example Usage:
user_id = "ValidUserID"
privilege_level = "Administrator"
forged_sso_token = forge_sso_token(user_id, privilege_level)
# Attacker submits the forged_sso_token to the affected system

Mitigation Steps

Cisco has released free software updates that address this vulnerability. Affected systems should be updated to a patched version as soon as possible.

Additionally, ensure proper access controls are in place, such as only giving users the least amount of privileges necessary to complete their tasks.

Conclusion

The CVE-2023-20238 vulnerability presents a significant security risk for organizations using affected Cisco BroadWorks systems. It is vital to update your systems with patches provided by Cisco, and to enforce robust access controls, to avoid unauthorized access and potential compromise of sensitive information.

Stay vigilant, and ensure your security practices remain up-to-date to counteract evolving threats.

Timeline

Published on: 09/06/2023 18:15:00 UTC
Last modified on: 09/14/2023 15:39:00 UTC