CVE-2024-8273

Executive Summary

CVE-2024-8273 is an Authentication Bypass by Spoofing vulnerability in HYPR Server, allowing an attacker to impersonate a legitimate identity. The flaw exists in versions prior to 10.1 and enables identity spoofing without proper authentication. The vulnerability has a CVSS score of 0.0 (likely unassigned or placeholder), but the impact is severe as it compromises the core authentication mechanism of the HYPR platform. No public proof-of-concept or exploit code is available at this time.

Supply Chain & Package Security

This vulnerability affects the HYPR Server software, which is a proprietary identity and access management solution. It is not an open-source package (NPM, PyPI, Go, Ruby), so supply chain package security considerations are not directly applicable. However, organizations using HYPR should verify the integrity of their deployment artifacts and ensure they are sourced from official channels.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unassigned)
• Attack Vector: Network (likely)
• Attack Complexity: Low (likely)
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Given the nature of the vulnerability (authentication bypass by spoofing), the threat level is Critical. An unauthenticated attacker can impersonate any user, leading to full compromise of the HYPR system and associated resources.

Deep Dive & Mechanics

The vulnerability resides in the authentication logic of HYPR Server versions before 10.1. It allows an attacker to bypass authentication by spoofing identity claims. The exact mechanism is not publicly disclosed, but it likely involves:

• Weak validation of identity tokens: The server may not properly verify the origin or integrity of authentication tokens.
• Spoofing of user identifiers: An attacker can craft requests that impersonate a legitimate user by manipulating identity fields.
• Lack of cryptographic verification: The server may accept unsigned or improperly signed authentication data.

This flaw enables an attacker to gain unauthorized access to the HYPR Server, potentially compromising all users and services relying on it.

Vulnerable vs. Patched Code

No specific code snippets are available. However, the patch in version 10.1 likely includes:

• Strict validation of authentication tokens: Ensuring tokens are cryptographically signed and verified.
• Origin checks: Verifying that identity claims come from trusted sources.
• Input sanitization: Preventing injection of spoofed identity data.

Exploitation & Lab Setup

Red Team

Since no public exploit code is available, a red team would need to reverse-engineer the authentication flow. A potential approach:

1. Identify the authentication endpoint: e.g., /auth/login or /api/authenticate.
2. Capture legitimate authentication traffic: Use a proxy like Burp Suite to observe token exchange.
3. Analyze token structure: Look for weaknesses in token generation (e.g., predictable values, lack of signature).
4. Craft spoofed requests: Modify identity claims (e.g., username, user ID) in the token or request body.
5. Test against a lab instance: Use a non-production HYPR Server (version < 10.1) to validate the bypass.

Example (hypothetical):

# Assuming a vulnerable endpoint that accepts a user_id parameter
curl -X POST https://target-hypr-server/auth/login \
  -H "Content-Type: application/json" \
  -d '{"user_id": "admin", "token": "spoofed_token"}'

Blue Team

1. Monitor authentication logs: Look for repeated failed attempts followed by successful logins from the same IP.
2. Detect anomalous identity claims: Alert on logins where the user_id or token does not match expected patterns.
3. Implement network segmentation: Isolate HYPR Server from untrusted networks.
4. Enable multi-factor authentication (MFA): Even if the bypass occurs, MFA can provide an additional layer.
5. Upgrade to version 10.1 immediately.

Indicators of Compromise (IOCs)

• Network IOCs:

  • Unusual authentication requests to HYPR Server endpoints.
  • Requests with manipulated identity fields (e.g., user_id, token).
  • Traffic from IPs not in the organization's trusted list.

• Host IOCs:

  • Unexpected user accounts created or accessed.
  • Log entries showing authentication bypass events (e.g., "Authentication successful" without prior challenge).
  • Modified configuration files related to authentication.

• File IOCs:

  • Suspicious log files with repeated authentication attempts.
  • Temporary files containing spoofed tokens.

Detection Engineering

YARA Rule

rule CVE_2024_8273_HYPR_Auth_Bypass {
    meta:
        description = "Detects potential exploitation of CVE-2024-8273 in HYPR Server logs"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-8273"
    strings:
        $s1 = "Authentication successful" nocase
        $s2 = "user_id=" nocase
        $s3 = "spoofed" nocase
        $s4 = "bypass" nocase
    condition:
        any of ($s1, $s2, $s3, $s4)
}

Sigma Rule

title: CVE-2024-8273 HYPR Server Authentication Bypass
id: 8a3f7c2e-5d1b-4a9f-8c6e-2b1d3f4a5c6e
status: experimental
description: Detects authentication bypass attempts against HYPR Server
author: Valters IT
date: 2025/04/10
logsource:
    product: hypr
    service: server
detection:
    selection:
        EventID: 4624  # Successful logon
        LogonType: 3   # Network
        TargetUserName: "*admin*"
    condition: selection
falsepositives:
    - Legitimate admin logins
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"CVE-2024-8273 HYPR Server Authentication Bypass Attempt"; flow:to_server,established; content:"/auth/login"; http_uri; content:"user_id"; http_client_body; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Upgrade HYPR Server to version 10.1 or later.
2. Workaround: If upgrade is not possible, restrict network access to the HYPR Server using firewall rules and VPN.
3. Monitoring: Enable detailed logging and monitor for suspicious authentication events.
4. Incident Response: If exploitation is suspected, isolate the affected server and conduct forensic analysis.
5. Long-term: Implement a vulnerability management program to ensure timely patching.

Valters IT