CVE-2021-27186 Explained : Impact and Mitigation

Fluent Bit 1.6.10 has a vulnerability that leads to a NULL pointer dereference when an flb_malloc return value is not validated by flb_avro.c or http_server/api/v1/metrics.c.

Understanding CVE-2021-27186

This CVE identifies a vulnerability in Fluent Bit version 1.6.10 that can result in a NULL pointer dereference due to unvalidated return values.

What is CVE-2021-27186?

CVE-2021-27186 is a vulnerability in Fluent Bit, where improper validation of flb_malloc return values can lead to a NULL pointer dereference, impacting the application's stability and performance.

The Impact of CVE-2021-27186

Exploitation of this vulnerability could potentially result in denial of service (DoS) attacks, system crashes, or tampering with system memory, posing a risk to the overall integrity and availability of the affected systems.

Technical Details of CVE-2021-27186

The technical details of CVE-2021-27186 include the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

Fluent Bit 1.6.10 experiences a NULL pointer dereference due to inadequate validation of flb_malloc return values, specifically in flb_avro.c or http_server/api/v1/metrics.c.

Affected Systems and Versions

The vulnerability impacts Fluent Bit version 1.6.10 when operating on systems where the return values of flb_malloc are not properly validated in the mentioned source files.

Exploitation Mechanism

By exploiting this vulnerability, threat actors can trigger a NULL pointer dereference in the affected components, potentially leading to service interruptions and system instability.

Mitigation and Prevention

To address CVE-2021-27186, immediate action is necessary to prevent exploitation and safeguard affected systems from potential threats.

Immediate Steps to Take

Developers and system administrators should prioritize validating all return values of flb_malloc in the affected components, namely flb_avro.c and http_server/api/v1/metrics.c.

Long-Term Security Practices

Implement secure coding practices, conduct regular security audits, and stay informed about patches and updates for Fluent Bit to enhance the overall security posture of the environment.

Patching and Updates

Ensure timely deployment of patches and updates released by Fluent Bit to mitigate the vulnerability and strengthen the resilience of the software against potential threats.