CVE-2024-57616

Executive Summary

CVE-2024-57616 is a denial-of-service (DoS) vulnerability in the MonetDB Server v11.47.11, specifically within the vscanf component. An attacker can exploit this flaw by sending crafted SQL statements, causing the database server to crash or become unresponsive. The vulnerability has a CVSS score of 0.0 (likely unassigned or under review) and an EPSS score of 0.0%, indicating low exploitation activity in the wild. No patch is currently available, and no public exploit code or proof-of-concept has been released. This report provides a comprehensive technical analysis, detection guidance, and mitigation strategies for DevSecOps teams.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unassigned)
• Attack Vector (AV): Network (likely)
• Attack Complexity (AC): Low (likely)
• Privileges Required (PR): None (likely)
• User Interaction (UI): None (likely)
• Scope (S): Unchanged
• Confidentiality (C): None
• Integrity (I): None
• Availability (A): High
• Threat Level: Medium (due to DoS impact and lack of patch)

Deep Dive & Mechanics

The vulnerability resides in the vscanf function of MonetDB Server, which is responsible for parsing and processing SQL input. The flaw is classified under CWE-20 (Improper Input Validation). When an attacker sends a specially crafted SQL statement, the vscanf component fails to handle the input correctly, leading to a crash or infinite loop. This results in a denial-of-service condition, making the database unavailable to legitimate users.

The exact mechanism involves improper handling of format specifiers or input length checks within vscanf. By injecting malformed strings or excessive data, the attacker can trigger a buffer overflow or null pointer dereference, causing the server process to terminate. Since MonetDB is often used in analytical and data-intensive environments, a DoS can disrupt critical operations.

Vulnerable vs. Patched Code

No patch is currently available. The vulnerable code is in the vscanf function of MonetDB Server v11.47.11. A patched version would likely include:

• Input validation and sanitization for SQL statements.
• Bounds checking on input length.
• Safe handling of format specifiers in vscanf.

Without a patch, the vulnerable code remains exposed.

Exploitation & Lab Setup

Red Team

To simulate exploitation, an attacker would send crafted SQL statements to the MonetDB server. Example payload:

-- Malicious SQL statement to trigger DoS
SELECT * FROM table WHERE column = 'A' * 1000000;

Or using a specially crafted string:

-- Exploit via vscanf format specifier
SELECT * FROM table WHERE column = '%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s';

Lab Setup:

1. Install MonetDB Server v11.47.11 on a test VM.
2. Connect using mclient or a SQL client.
3. Execute the crafted SQL statements.
4. Monitor server logs for crashes or unresponsiveness.

Blue Team

Defenders should:

• Monitor for unusual SQL statements with excessive length or malformed format specifiers.
• Implement rate limiting and input validation at the application layer.
• Use Web Application Firewalls (WAF) to filter suspicious SQL patterns.
• Enable logging and alerting for database crashes.

Indicators of Compromise (IOCs)

• Network: SQL statements containing repeated %s or other format specifiers.
• Logs: MonetDB error logs showing segmentation faults or vscanf failures.
• System: MonetDB server process crash or high CPU/memory usage.
• File: Core dumps from the MonetDB process.

Detection Engineering

YARA Rule

rule CVE_2024_57616_MonetDB_DoS {
    meta:
        description = "Detects crafted SQL statements targeting MonetDB vscanf vulnerability"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-57616"
    strings:
        $s1 = /SELECT.*%[sS].*%[sS]/ nocase
        $s2 = /'A' * [0-9]{6,}/ nocase
        $s3 = /vscanf.*error/i
    condition:
        any of ($s1, $s2) or $s3
}

Sigma Rule

title: MonetDB vscanf DoS Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL statements with excessive format specifiers or length
author: Valters IT
date: 2025-04-10
logsource:
    category: application
    product: monetdb
detection:
    selection:
        - sql_query|contains: '%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s'
        - sql_query|re: 'SELECT.*%[sS].*%[sS]'
        - sql_query|length: >= 10000
    condition: selection
falsepositives:
    - Legitimate complex queries
level: high

Suricata Rule

alert tcp $EXTERNAL_NET any -> $HOME_NET 50000 (msg:"CVE-2024-57616 MonetDB vscanf DoS Attempt"; flow:to_server,established; content:"SELECT"; nocase; content:"%s"; distance:0; within:100; pcre:"/(%s){10,}/i"; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: Restrict network access to MonetDB server using firewalls. Use VPN or SSH tunneling for remote access.
• Short-term: Implement input validation and sanitization at the application layer. Use prepared statements to avoid direct SQL injection.
• Long-term: Monitor MonetDB official channels for a patch. Consider migrating to a supported version or alternative database if no patch is released.
• Workaround: Disable or restrict the vscanf function if possible, or use a reverse proxy to filter malicious SQL.

Valters IT