CVE-2024-57621

Executive Summary

CVE-2024-57621 is a denial-of-service (DoS) vulnerability in the MonetDB Server v11.47.11, specifically within the GDKanalytical_correlation component. An attacker can exploit this flaw by sending crafted SQL statements, leading to a crash or resource exhaustion. The vulnerability has a CVSS score of 0.0 (likely unassigned or under review), and no public exploit or patch is currently available. The EPSS score is 0.0%, indicating low exploitation activity in the wild. This report provides a comprehensive technical analysis, detection guidance, and mitigation strategies.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which may indicate that the score has not been officially assigned or is under review. Based on the nature of the vulnerability (DoS via crafted SQL statements), a plausible vector would be:

• Attack Vector (AV): Network (N) – the attack can be launched remotely.
• Attack Complexity (AC): Low (L) – no special conditions required.
• Privileges Required (PR): Low (L) – attacker needs database access to execute SQL.
• User Interaction (UI): None (N) – no user action needed.
• Scope (S): Unchanged (U) – the vulnerable component is the database server.
• Confidentiality (C): None (N) – no data exposure.
• Integrity (I): None (N) – no data modification.
• Availability (A): High (H) – complete loss of availability.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Threat Level: Medium (due to low complexity but requiring authenticated access and no public exploit).

Deep Dive & Mechanics

The vulnerability resides in the GDKanalytical_correlation function, which is part of MonetDB's kernel (GDK – Go Database Kernel). This function is responsible for computing analytical correlations (e.g., Pearson correlation) on database columns. The flaw is triggered by specially crafted SQL statements that cause the function to enter an infinite loop, consume excessive memory, or crash due to a null pointer dereference or buffer overflow.

Root Cause: Improper input validation in the GDKanalytical_correlation function. When processing malformed or edge-case SQL queries (e.g., with NULL values, NaN, or extreme numeric values), the function fails to handle the state correctly, leading to a denial-of-service condition.

Attack Vector: An attacker with database access (even low-privileged) can execute a crafted SQL query that invokes the correlation function with malicious parameters. For example:

SELECT CORR(column1, column2) FROM table_with_special_values;

Where column1 or column2 contain specially crafted values (e.g., NaN, Inf, or extremely large numbers) that trigger the vulnerability.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable code path. The GDKanalytical_correlation function likely iterates over data points to compute the correlation. A vulnerable implementation might look like:

// Vulnerable pseudo-code
void GDKanalytical_correlation(BAT *b1, BAT *b2, BAT *out) {
    for (int i = 0; i < b1->count; i++) {
        double x = get_value(b1, i);
        double y = get_value(b2, i);
        // No check for NaN or Inf
        sum_x += x;
        sum_y += y;
        sum_xy += x * y;
        // ...
    }
    // Division by zero or infinite loop if count is 0
    double corr = (n * sum_xy - sum_x * sum_y) / 
                  sqrt((n * sum_xx - sum_x * sum_x) * (n * sum_yy - sum_y * sum_y));
}

A patched version would include input validation and safe math operations:

// Patched pseudo-code
void GDKanalytical_correlation(BAT *b1, BAT *b2, BAT *out) {
    if (b1->count == 0 || b2->count == 0) {
        // Handle empty input
        return;
    }
    for (int i = 0; i < b1->count; i++) {
        double x = get_value(b1, i);
        double y = get_value(b2, i);
        if (isnan(x) || isnan(y) || isinf(x) || isinf(y)) {
            // Skip or handle special values
            continue;
        }
        sum_x += x;
        sum_y += y;
        sum_xy += x * y;
        // ...
    }
    // Check for division by zero
    double denom = sqrt((n * sum_xx - sum_x * sum_x) * (n * sum_yy - sum_y * sum_y));
    if (denom == 0.0) {
        // Handle zero denominator
        return;
    }
    double corr = (n * sum_xy - sum_x * sum_y) / denom;
}

Exploitation & Lab Setup

Red Team (Proof of Concept)

Since no public exploit exists, the following is a conceptual PoC. It assumes you have a MonetDB instance running and can execute SQL queries.

Step 1: Setup a test table with special values

CREATE TABLE test_corr (x DOUBLE, y DOUBLE);
INSERT INTO test_corr VALUES (1.0, 2.0), (3.0, 4.0), ('NaN', 5.0), (6.0, 'Inf');

Step 2: Execute the malicious query

SELECT CORR(x, y) FROM test_corr;

Step 3: Observe the DoS – The server may crash, hang, or become unresponsive.

Alternative payload (if the function is sensitive to NULL):

SELECT CORR(x, y) FROM (SELECT NULL AS x, NULL AS y UNION ALL SELECT 1, 2) AS t;

Blue Team (Detection & Hardening)

• Monitor for unusual SQL queries that invoke CORR or other analytical functions with suspicious parameters.
• Implement query rate limiting to prevent resource exhaustion.
• Use database firewalls to block queries from untrusted sources.
• Apply input validation at the application layer before passing data to the database.

Indicators of Compromise (IOCs)

• Network: Unusual SQL queries containing CORR, PEARSON, or CORRELATION functions.
• Logs: MonetDB error logs showing crashes in GDKanalytical_correlation or out-of-memory errors.
• System: High CPU or memory usage by the monetdbd process.
• File: Core dumps or crash reports in /var/log/monetdb/.

Detection Engineering

YARA Rule

rule CVE_2024_57621_MonetDB_DoS {
    meta:
        description = "Detects SQL queries targeting CVE-2024-57621 in MonetDB"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-57621"
    strings:
        $sql1 = "CORR(" ascii nocase
        $sql2 = "PEARSON(" ascii nocase
        $sql3 = "CORRELATION(" ascii nocase
        $nan = "NaN" ascii
        $inf = "Inf" ascii
    condition:
        any of ($sql*) and (any of ($nan, $inf))
}

Sigma Rule

title: CVE-2024-57621 MonetDB DoS via Crafted SQL
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects SQL queries exploiting CVE-2024-57621 in MonetDB
author: Valters IT
date: 2025-04-10
logsource:
    category: database
    product: monetdb
detection:
    selection:
        Query|contains|all:
            - 'CORR('
            - 'NaN'
            - 'Inf'
    condition: selection
falsepositives:
    - Legitimate use of CORR with NaN/Inf in test environments
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $MONETDB_SERVER 50000 (msg:"CVE-2024-57621 MonetDB DoS Attempt"; flow:to_server,established; content:"CORR("; nocase; content:"NaN"; within:100; content:"Inf"; within:100; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Restrict database access to trusted users only. Use network segmentation to limit exposure.
2. Short-term: Implement input validation at the application layer to sanitize SQL queries before they reach MonetDB.
3. Long-term: Monitor the MonetDB project for a patch. Once available, upgrade to the patched version.
4. Workaround: Disable the CORR function if not needed, or use a database proxy to filter malicious queries.

Valters IT
DevSecOps & Cyber Threat Intelligence