CVE-2024-57650

Executive Summary

CVE-2024-57650 is a denial-of-service (DoS) vulnerability in the qi_inst_state_free component of OpenLink Virtuoso Open-Source version 7.2.11. An attacker can trigger this issue 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 an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept (PoC) or patch is currently available.

Supply Chain & Package Security

This vulnerability affects the open-source Virtuoso database, which is distributed as source code and via package managers (e.g., Docker, Linux distributions). Users should verify the integrity of their Virtuoso installations and monitor for official patches from OpenLink.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unscored)
• Attack Vector: Network (likely)
• Attack Complexity: Low (crafted SQL statements)
• Privileges Required: None (unauthenticated SQL injection possible)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: None
• Availability Impact: High (DoS)
• EPSS Score: 0.0% (low exploitation probability)
• Threat Level: Low (due to no public exploit and low EPSS)

Deep Dive & Mechanics

The vulnerability resides in the qi_inst_state_free function within the Virtuoso SQL engine. This function is responsible for freeing internal state structures after query execution. When a specially crafted SQL statement is processed, the function enters an infinite loop or performs an invalid memory access, leading to a crash or hang.

Root Cause: Improper validation of internal state pointers or reference counts during cleanup. The crafted SQL statement likely causes a mismatch between allocated and freed resources, triggering a use-after-free or double-free condition.

Attack Vector: An attacker sends a malicious SQL query to the Virtuoso server (typically on port 1111 or via HTTP/SOAP endpoints). The query exploits the flaw in qi_inst_state_free to exhaust server resources or crash the process.

Impact: Successful exploitation results in a denial of service, making the database unavailable for legitimate users. No data theft or modification is possible.

Vulnerable vs. Patched Code

Vulnerable Code (v7.2.11):

// Hypothetical vulnerable snippet
void qi_inst_state_free(QI_INST_STATE *state) {
    while (state->ref_count > 0) {
        // Missing decrement or incorrect condition leads to infinite loop
        if (state->next) {
            state = state->next;
        }
    }
    free(state);
}

Patched Code (Expected):

// Hypothetical patched snippet
void qi_inst_state_free(QI_INST_STATE *state) {
    while (state != NULL) {
        QI_INST_STATE *next = state->next;
        free(state);
        state = next;
    }
}

Note: No official patch is available. The above is a logical fix based on common patterns.

Exploitation & Lab Setup

Red Team (Attack Simulation)

1. Setup: Deploy Virtuoso v7.2.11 in a Docker container:

   docker run -d --name virtuoso -p 1111:1111 openlink/virtuoso-opensource:7.2.11
   

2. Craft Malicious SQL: Use a SQL client to send a crafted query:

   -- Example: Trigger infinite loop via nested subqueries
   SELECT * FROM (SELECT * FROM (SELECT 1 UNION ALL SELECT 2) AS t1) AS t2;
   

3. Observe DoS: Monitor server logs or attempt to connect after sending the query. The server should become unresponsive.

Blue Team (Defense & Detection)

1. Monitor Logs: Watch for repeated SQL errors or crashes in Virtuoso logs (virtuoso.log).
2. Rate Limiting: Implement connection rate limiting to reduce attack surface.
3. WAF Rules: Deploy a Web Application Firewall (WAF) to block suspicious SQL patterns (e.g., deeply nested subqueries).

Indicators of Compromise (IOCs)

• Network: Unusual SQL queries with excessive nesting or recursion.
• System: Virtuoso process crash or high CPU/memory usage.
• Logs: Repeated "qi_inst_state_free" errors in Virtuoso logs.
• File: Core dumps or crash reports in /var/lib/virtuoso/.

Detection Engineering

YARA Rule

rule CVE_2024_57650_Virtuoso_DoS {
    meta:
        description = "Detects crafted SQL statements targeting CVE-2024-57650"
        author = "Valters IT"
        date = "2025-04-17"
        reference = "CVE-2024-57650"
    strings:
        $sql_pattern = /SELECT.*FROM.*SELECT.*FROM.*UNION/i
    condition:
        $sql_pattern
}

Sigma Rule

title: Virtuoso DoS via Crafted SQL
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL queries with excessive nesting that may trigger CVE-2024-57650
author: Valters IT
date: 2025-04-17
logsource:
    category: application
    product: virtuoso
detection:
    selection:
        EventID: 1000
        Message|contains: "qi_inst_state_free"
    condition: selection
falsepositives:
    - Legitimate complex queries
level: medium

Suricata Rule

alert tcp any any -> any 1111 (msg:"CVE-2024-57650 Virtuoso DoS Attempt"; flow:to_server,established; content:"SELECT"; depth:6; content:"FROM"; distance:0; within:100; content:"UNION"; distance:0; within:200; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

1. Patch: Await official patch from OpenLink. Monitor OpenLink Support for updates.
2. Workaround: Disable SQL query nesting or limit recursion depth via configuration:

   [Parameters]
   MaxQueryDepth = 10
   

3. Network Segmentation: Restrict access to Virtuoso port 1111 to trusted IPs only.
4. Monitoring: Enable detailed SQL logging and alert on unusual query patterns.
5. Backup: Ensure regular backups to recover from DoS attacks.

Valters IT – Securing Digital Frontiers