CVE-2021-31294 : Exploit Details and Defense Strategies
Learn about CVE-2021-31294, a vulnerability in Redis before 6cbea7d allowing unauthorized replicas to trigger an assertion failure in a primary server by sending non-administrative commands.
A detailed article on CVE-2021-31294, including its description, impact, technical details, mitigation, and prevention methods.
Understanding CVE-2021-31294
In this section, we will delve into the specifics of CVE-2021-31294.
What is CVE-2021-31294?
The vulnerability in Redis before 6cbea7d allows a replica to trigger an assertion failure in a primary server by sending a non-administrative command (specifically, a SET command). This issue was addressed in Redis 6.2.x and 7.x starting in 2021, with versions before 6.2 lacking safety guarantees related to this issue.
The Impact of CVE-2021-31294
The vulnerability can lead to a critical security risk where unauthorized replicas can exploit Redis servers, compromising their integrity and availability.
Technical Details of CVE-2021-31294
This section covers the technical aspects of CVE-2021-31294.
Vulnerability Description
The vulnerability allows a replica to cause an assertion failure in a primary Redis server using a non-administrative command like SET, potentially leading to service disruption or unauthorized access.
Affected Systems and Versions
All versions of Redis prior to 6.2 are susceptible to this vulnerability, with versions before 6.2 lacking safety guarantees.
Exploitation Mechanism
By sending a specific non-administrative command, such as SET, an unauthorized replica can exploit this vulnerability to disrupt the primary Redis server.
Mitigation and Prevention
This section outlines strategies to mitigate and prevent exploitation of CVE-2021-31294.
Immediate Steps to Take
- Update Redis to version 6.2.x or 7.x to patch the vulnerability.
- Monitor Redis server logs for any unusual activity.
Long-Term Security Practices
- Regularly update and patch Redis to stay protected from known vulnerabilities.
- Implement network segmentation to restrict access to Redis servers.
Patching and Updates
Stay informed about security advisories and apply patches promptly to ensure the security of your Redis infrastructure.