CVE-2024-20419: Cisco SSM On-Prem Auth Bypass Flaw

CVE-2024-20419 Overview

A critical authentication bypass vulnerability exists in the authentication system of 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 is due to improper implementation of the password-change process, enabling attackers to send crafted HTTP requests to an affected device. A successful exploit could allow an attacker to access the web UI or API with the privileges of the compromised user.

Critical Impact

Unauthenticated remote attackers can change any user password, including administrators, gaining full access to the Cisco SSM On-Prem web UI and API without requiring any credentials.

Affected Products

• Cisco Smart Software Manager On-Prem (SSM On-Prem)

Discovery Timeline

• 2024-07-17 - CVE-2024-20419 published to NVD
• 2025-07-31 - Last updated in NVD database

Technical Details for CVE-2024-20419

Vulnerability Analysis

This authentication bypass vulnerability (CWE-620: Unverified Password Change) represents a severe implementation flaw in the password-change process of Cisco Smart Software Manager On-Prem. The vulnerability allows unauthenticated attackers to remotely change the password of any user account without proper verification of the requester's identity or authorization to perform such actions.

The flaw exists because the password-change endpoint fails to properly validate that the user requesting the password change is actually the account owner or has legitimate authorization to modify credentials. This allows attackers to craft malicious HTTP requests that bypass standard authentication controls entirely.

Root Cause

The root cause of CVE-2024-20419 is an improper implementation of the password-change process within the authentication system. The application fails to enforce proper identity verification before allowing password modifications, violating the fundamental security principle that users should only be able to change their own passwords after proper authentication. This represents a classic Unverified Password Change vulnerability (CWE-620), where the system accepts password change requests without adequately verifying the identity of the requestor.

Attack Vector

The attack is conducted remotely over the network without requiring any prior authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests to the vulnerable Cisco SSM On-Prem instance. The attack requires no privileges and can be executed with low complexity.

The exploitation flow involves:

1. The attacker identifies a Cisco SSM On-Prem instance accessible over the network
2. The attacker crafts malicious HTTP requests targeting the password-change functionality
3. The vulnerable system processes the request without proper identity verification
4. The attacker successfully changes the password of a target user (including administrators)
5. The attacker logs into the web UI or accesses the API with the compromised user's privileges

Since the vulnerability affects administrative accounts, successful exploitation grants attackers complete control over the software licensing management system. For detailed technical information, refer to the Cisco Security Advisory.

Detection Methods for CVE-2024-20419

Indicators of Compromise

• Unexpected password change events in SSM On-Prem audit logs, particularly for administrative accounts
• Anomalous HTTP requests to password-change endpoints from external or unusual IP addresses
• Administrative account access from previously unseen locations or at unusual times
• Multiple failed login attempts followed by successful password changes without legitimate user requests

Detection Strategies

• Monitor SSM On-Prem authentication logs for password change events that were not initiated through normal administrative procedures
• Implement network-level detection for suspicious HTTP traffic patterns targeting SSM On-Prem password-change endpoints
• Deploy intrusion detection/prevention systems with signatures for CVE-2024-20419 exploitation attempts
• Enable alerting on administrative account modifications and correlate with user activity logs

Monitoring Recommendations

• Configure SIEM rules to alert on password changes for privileged accounts in SSM On-Prem
• Establish baseline network traffic patterns to/from SSM On-Prem instances to identify anomalies
• Implement real-time monitoring of administrative access to the SSM On-Prem web UI and API
• Review access logs regularly for signs of unauthorized access following password changes

How to Mitigate CVE-2024-20419

Immediate Actions Required

• Upgrade Cisco Smart Software Manager On-Prem to the latest patched version immediately
• Restrict network access to SSM On-Prem instances to trusted networks only
• Review all user accounts, especially administrative accounts, for unauthorized password changes
• Implement additional authentication controls such as multi-factor authentication where possible
• Monitor for exploitation attempts while patching is in progress

Patch Information

Cisco has released security updates to address this vulnerability. Organizations should apply the patch as soon as possible given the critical nature and network-exploitable characteristics of this vulnerability. Refer to the Cisco Security Advisory (cisco-sa-cssm-auth-sLw3uhUy) for specific version information and download links.

Workarounds

• Isolate SSM On-Prem instances behind firewalls and restrict access to authorized management networks only
• Implement network segmentation to limit exposure of SSM On-Prem to the minimum necessary network scope
• Use access control lists (ACLs) to whitelist only trusted IP addresses that require access to SSM On-Prem
• Monitor and audit all administrative access until the patch can be applied

# Example: Restrict access to SSM On-Prem using firewall rules
# Allow access only from trusted management network
iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP

# Alternatively, use ACL on network devices to restrict access
# access-list SSM-RESTRICT permit tcp 10.10.10.0 0.0.0.255 host SSM-SERVER eq 443
# access-list SSM-RESTRICT deny tcp any host SSM-SERVER eq 443