CVE-2024-38890

Executive Summary

CVE-2024-38890 is an authentication bypass vulnerability in Horizon Business Services Inc. Caterease Software, affecting versions 16.0.1.1663 through 24.0.1.2405 and possibly later versions. The vulnerability allows a local attacker to perform an Authentication Bypass by Capture-replay attack due to insufficient protection against capture-replay attacks. This means an attacker with local access to the network traffic can capture a valid authentication session and replay it to gain unauthorized access to the application. The CVSS score is 0.0, indicating that no official CVSS vector has been assigned, but the impact is significant as it compromises authentication integrity. No public exploit code or proof-of-concept is available at this time.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official vector assigned)
• Attack Vector (AV): Local (L) – The attacker must have local network access to capture traffic.
• Attack Complexity (AC): Low (L) – Replaying captured packets is straightforward.
• Privileges Required (PR): None (N) – No prior authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerability affects the same security authority.
• Confidentiality (C): High (H) – Successful replay can lead to full access to user data.
• Integrity (I): High (H) – Attacker can perform actions as the victim.
• Availability (A): None (N) – No direct impact on availability.
• Threat Level: High – Authentication bypass can lead to complete account takeover.

Deep Dive & Mechanics

The vulnerability stems from insufficient protection against capture-replay attacks in Caterease Software's authentication mechanism. When a user authenticates, the session token or authentication credentials are transmitted over the network without proper replay protection (e.g., nonce, timestamp, or one-time use tokens). A local attacker who can sniff the network traffic (e.g., on a shared LAN or via ARP spoofing) can capture the authentication exchange. By replaying the captured packets, the attacker can impersonate the legitimate user and gain unauthorized access to the application.

The affected versions span from 16.0.1.1663 to 24.0.1.2405, indicating a long-standing architectural flaw. The lack of a patch suggests the vendor may not have addressed this issue, or the patch is not publicly available.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code likely lacks mechanisms such as:

• Nonce/Timestamp: A unique, time-limited token that must be included in each authentication request.
• Session Binding: Tying the session to a specific client IP or device fingerprint.
• One-Time Use Tokens: Ensuring each authentication token can only be used once.

A patched version would implement one or more of these protections to prevent replay attacks.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Local network access to the Caterease server and client traffic.
• Ability to capture network packets (e.g., using Wireshark, tcpdump, or a man-in-the-middle tool like Bettercap).

Steps:

1. Capture Authentication Traffic: Use a packet sniffer to capture traffic between a legitimate client and the Caterease server during authentication.

   sudo tcpdump -i eth0 -w auth_capture.pcap host <server_ip> and port <caterease_port>
   

2. Extract Authentication Data: Open the pcap file in Wireshark and filter for the authentication exchange. Look for the session token or credentials in the payload.
3. Replay the Authentication: Use a tool like tcpreplay or a custom script to replay the captured packets to the server.

   tcpreplay -i eth0 auth_capture.pcap
   

4. Verify Access: After replay, the attacker should be authenticated as the victim user and can access the application.

Note: No public exploit code is available, so this is a generic methodology.

Blue Team (Defense)

Detection:

• Monitor for multiple authentication attempts from the same IP within a short time window.
• Detect replay attacks by checking for identical authentication packets (e.g., same sequence numbers, timestamps, or payloads).
• Use network intrusion detection systems (NIDS) to flag repeated authentication requests.

Mitigation:

• Implement nonce-based authentication where each request includes a unique, time-limited token.
• Enforce session binding to client IP or device fingerprint.
• Use TLS to encrypt traffic, making capture harder but not preventing replay if the token is still reusable.
• Deploy application-layer firewalls to rate-limit authentication attempts.

Indicators of Compromise (IOCs)

• Network Traffic: Multiple identical authentication packets from different source IPs or within a short time.
• Logs: Repeated successful logins for the same user from different IPs or at unusual times.
• Session Tokens: Reused session tokens across different client IPs.
• File Hashes: No specific file hashes available.
• IP Addresses: Any IP that replays captured traffic.

Detection Engineering

YARA Rule

rule CVE_2024_38890_Caterease_Replay {
    meta:
        description = "Detects potential capture-replay attack traffic for Caterease authentication"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-38890"
    strings:
        $auth_pattern = /Caterease.*(?:login|auth|session)/ nocase
        $replay_indicator = /(?:token|session|auth).*replay/ nocase
    condition:
        $auth_pattern and #replay_indicator > 2
}

Sigma Rule

title: Caterease Authentication Replay Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects multiple identical authentication packets from different sources
logsource:
    category: network_flow
    product: suricata
detection:
    selection:
        app_protocol: 'http'
        http.method: 'POST'
        http.uri: '/login'
    condition: selection
    timeframe: 5m
    aggregation:
        - field: http.user_agent
          condition: distinct_count > 1
falsepositives:
    - Legitimate load balancers
level: high

Suricata Rule

alert tcp any any -> any 80 (msg:"CVE-2024-38890 Caterease Authentication Replay Attempt"; flow:to_server; content:"POST"; http_method; content:"/login"; http_uri; content:"Caterease"; http_user_agent; threshold: type both, track by_src, count 5, seconds 60; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate Affected Systems: If possible, restrict network access to Caterease servers to trusted IPs only.
2. Enable TLS: Ensure all Caterease traffic is encrypted using TLS to make packet capture harder.
3. Implement Network Segmentation: Place Caterease servers on a separate VLAN to limit local attacker access.

Long-Term Fix:

• Vendor Patch: Contact Horizon Business Services Inc. for a patch that implements nonce-based authentication or one-time tokens.
• Custom Wrapper: If patching is not possible, deploy a reverse proxy that adds replay protection (e.g., mod_security with anti-replay rules).
• Upgrade: Consider migrating to a different software solution if the vendor does not provide a fix.

Workaround:

• Use VPN or SSH tunneling for all Caterease connections to add an extra layer of encryption and authentication.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert