CVE-2024-57622

Executive Summary

CVE-2024-57622 is a denial-of-service (DoS) vulnerability in the exp_bin component of MonetDB Server v11.49.1. An attacker can trigger a crash or resource exhaustion by sending specially crafted SQL statements that exploit improper input validation in the binary expression evaluator. No public exploit code or patch is currently available. The vulnerability has a CVSS score of 0.0 (unscored) and an EPSS score of 0.0%, indicating low exploitation activity at this time.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unscored)
• Attack Vector: Network (likely)
• Attack Complexity: Low (likely)
• Privileges Required: None (likely)
• User Interaction: None (likely)
• Scope: Unchanged (likely)
• Confidentiality Impact: None
• Integrity Impact: None
• Availability Impact: High
• Threat Level: Medium (due to potential for service disruption)

Deep Dive & Mechanics

The vulnerability resides in the exp_bin component of MonetDB Server, which handles binary expressions (e.g., arithmetic, logical, comparison operations). The flaw is a classic input validation issue (CWE-20): the component fails to properly sanitize or validate certain crafted SQL statements, leading to undefined behavior such as memory corruption, infinite loops, or segmentation faults.

Technical Details:

• The exp_bin function processes binary operations like +, -, *, /, AND, OR, etc.
• A malicious SQL statement can cause the function to enter an unexpected state, consuming excessive CPU or memory, or crashing the server process.
• The exact trigger mechanism is not publicly documented, but it likely involves deeply nested expressions, type coercion edge cases, or division-by-zero scenarios that are not properly handled.

Attack Vector:

• An unauthenticated attacker sends a crafted SQL query to the MonetDB server (default port 50000).
• The query is parsed and executed, triggering the bug in exp_bin.
• The server becomes unresponsive or crashes, causing a denial of service.

Vulnerable vs. Patched Code

Since no patch is available, a direct code comparison cannot be made. However, based on the vulnerability description, the fix would likely involve:

• Adding input validation for binary expression operands.
• Implementing bounds checking for nested expression depth.
• Handling edge cases like division by zero, overflow, or type mismatches gracefully.
• Introducing resource limits (e.g., recursion depth, memory usage) for expression evaluation.

Hypothetical vulnerable code pattern (C):

// Vulnerable: no check for NULL or invalid types
ValPtr exp_bin(Expression *e) {
    ValPtr left = evaluate(e->left);
    ValPtr right = evaluate(e->right);
    // Direct operation without validation
    return perform_operation(left, right, e->op);
}

Hypothetical patched code pattern (C):

// Patched: validate operands before operation
ValPtr exp_bin(Expression *e) {
    ValPtr left = evaluate(e->left);
    ValPtr right = evaluate(e->right);
    if (!left || !right || left->type != right->type) {
        return error("Invalid operands");
    }
    if (e->op == OP_DIV && right->value == 0) {
        return error("Division by zero");
    }
    return perform_operation(left, right, e->op);
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

Lab Environment:

• MonetDB Server v11.49.1 running on Ubuntu 22.04
• Network access to port 50000

Exploitation Steps:

1. Connect to the MonetDB server using mclient or a custom script.
2. Send a crafted SQL statement designed to trigger the exp_bin bug. Example (hypothetical):

   SELECT 1/0;  -- Division by zero (may or may not trigger)
   

   Or a deeply nested expression:

   SELECT (((((((((1+1)+1)+1)+1)+1)+1)+1)+1)+1;
   

3. Monitor server response. If the server crashes or becomes unresponsive, the DoS is successful.

Proof-of-Concept (Python):

import socket

def exploit(target_ip, target_port=50000):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((target_ip, target_port))
    # Crafted SQL to trigger DoS (hypothetical)
    payload = "SELECT 1/0;\n"
    sock.send(payload.encode())
    response = sock.recv(4096)
    print(response.decode())
    sock.close()

if __name__ == "__main__":
    exploit("192.168.1.100")

Blue Team (Defense & Detection)

Detection:

• Monitor for repeated failed SQL queries or unusual query patterns.
• Set up alerts for server crashes or high CPU/memory usage.
• Use network monitoring to detect connections to port 50000 from untrusted sources.

Mitigation:

• Restrict network access to the MonetDB server using firewalls.
• Implement rate limiting for SQL queries.
• Apply input validation and sanitization at the application layer.
• Monitor for patches from MonetDB and apply them promptly.

Indicators of Compromise (IOCs)

• Network: Connections to port 50000 (MonetDB default) from suspicious IPs.
• Logs: MonetDB error logs showing segmentation faults, out-of-memory errors, or repeated query failures.
• System: High CPU or memory usage by the monetdbd or mserver5 processes.
• File: Core dump files in the MonetDB data directory.

Detection Engineering

YARA Rule

rule CVE_2024_57622_MonetDB_DoS {
    meta:
        description = "Detects MonetDB server crash logs indicating CVE-2024-57622 exploitation"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-57622"
    strings:
        $crash1 = "segmentation fault" nocase
        $crash2 = "SIGSEGV" nocase
        $crash3 = "out of memory" nocase
        $crash4 = "exp_bin" nocase
    condition:
        any of ($crash*) and filesize < 1MB
}

Sigma Rule

title: MonetDB DoS via CVE-2024-57622
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects potential exploitation of CVE-2024-57622 in MonetDB logs
author: Valters IT
date: 2025-04-10
logsource:
    product: monetdb
    service: monetdbd
detection:
    selection:
        EventID: 1
        Message|contains:
            - 'segmentation fault'
            - 'SIGSEGV'
            - 'out of memory'
            - 'exp_bin'
    condition: selection
falsepositives:
    - Legitimate server crashes due to other bugs
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET 50000 (msg:"CVE-2024-57622 MonetDB DoS Attempt"; flow:to_server,established; content:"SELECT"; nocase; content:"/"; distance:0; within:10; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Restrict network access to the MonetDB server using firewall rules. Only allow trusted IPs.
2. Short-term: Monitor for official patches from MonetDB. Apply input validation at the application layer.
3. Long-term: Upgrade to a patched version once available. Implement robust input sanitization for all SQL queries.
4. Workaround: If patching is not possible, consider using a reverse proxy or WAF to filter malicious SQL patterns.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert