A newly discovered vulnerability in MonetDB Server versions v11.45.17 and v11.46. has been assigned CVE-2023-36367. This severe security issue lies in the BLOBcmp component and can enable attackers to cause a Denial of Service (DoS) attack through carefully crafted SQL statements. In this long-read post, we will explore the specifics of this vulnerability, its potential impact on systems running affected MonetDB Server versions, and how to mitigate this risk.

Vulnerability Details

CVE-2023-36367 resides in the BLOBcmp component, a crucial part of MonetDB, an open-source column-store database management system (DBMS) that prides itself on its robust performance and scalability. MonetDB is typically used for analytical applications and data warehouse scenarios, making it an attractive target for malicious threat actors who may wish to disrupt large-scale data processing.

The vulnerability exists due to improper validation of input in the "BLOBcmp" function. Attackers can exploit this weakness by sending specially crafted SQL statements that include large Binary Large Objects (BLOBs) which the server may not handle correctly. This can result in excessive memory consumption, ultimately triggering a DoS condition.

The following code snippet demonstrates a basic PoC of CVE-2023-36367


    id INTEGER,
    data BLOB

-- The following SQL statement contains a crafted BLOB value, exploiting the BLOBcmp vulnerability:
INSERT INTO tbl (id, data) VALUES
(1, 'x50...00'),

-- Additional data fields can be inserted here for further exploitation and induced DoS...

-- Trigger a query that utilizes the BLOBcmp function, causing the server to crash
SELECT * FROM tbl WHERE data = 'x50...00';

To understand more about this code, you can refer to the official documentation on MonetDB SQL Syntax.

Original References

- CVE-2023-36367's entry on the National Vulnerability Database (NVD)
- MonetDB's official website


The MonetDB development team is aware of CVE-2023-36367 and has released patches to address the issue. It is crucial for administrators running affected MonetDB Server versions to update their installations to the latest available release. You can obtain the updated version of MonetDB from their official download page.


CVE-2023-36367 is a severe security vulnerability affecting MonetDB Server v11.45.17 and v11.46. that can enable attackers to cause a DoS attack through crafted SQL statements. Systems with affected MonetDB versions should be updated immediately to avoid exposure to this threat. Always exercise caution when dealing with untrusted input and maintain a proactive security posture to minimize potential attack vectors.


Published on: 06/22/2023 14:15:00 UTC
Last modified on: 06/28/2023 18:49:00 UTC