CVE-2021-32040 : What You Need to Know

A detailed analysis of CVE-2021-32040 related to a vulnerability in MongoDB Server versions prior to 5.0.4, 4.4.11, 4.2.16 that could lead to a denial of service (DoS) attack.

Understanding CVE-2021-32040

This section provides insights into the nature and impact of the CVE-2021-32040 vulnerability.

What is CVE-2021-32040?

The vulnerability arises from the possibility of causing a stack overflow in MongoDB due to the size of stack frames used by an extremely long aggregation pipeline with a specific stage/operator. Attackers could exploit this to maliciously crash MongoDB servers, impacting availability.

The Impact of CVE-2021-32040

The impact of this vulnerability is rated as medium with a CVSS base score of 6.5. While it requires low privileges to exploit, its network attack vector and high availability impact make it a significant threat to MongoDB deployments.

Technical Details of CVE-2021-32040

Explore the technical aspects and implications of CVE-2021-32040 in MongoDB environments.

Vulnerability Description

The vulnerability stems from a stack-based buffer overflow (CWE-121) in MongoDB Server, affecting versions less than 5.0.4, 4.4.11, and 4.2.16. An attacker can trigger a crash by leveraging a specific aggregation pipeline structure.

Affected Systems and Versions

MongoDB Server versions 4.2.16, 4.4.11, and below 5.0.4 are vulnerable to this issue, which could result in service disruption and potential data loss.

Exploitation Mechanism

By crafting a lengthy aggregation pipeline with a particular stage, threat actors can induce a stack overflow leading to MongoDB crashes, impacting service availability.

Mitigation and Prevention

Learn about the necessary steps to mitigate the CVE-2021-32040 vulnerability and enhance MongoDB security.

Immediate Steps to Take

Users of affected versions, especially prior to 4.2.16, should implement a workaround by adjusting the internal pipeline length limit to prevent crashes. Upgrading to versions beyond 5.0.4 is recommended.

Long-Term Security Practices

Developing and enforcing secure coding practices, monitoring for unusual aggregation patterns, and staying informed about MongoDB security updates are crucial for long-term protection.

Patching and Updates

Regularly apply patches provided by MongoDB Inc. and stay abreast of security advisories to address vulnerabilities promptly.