CVE-2021-33195 : What You Need to Know

Go before 1.15.13 and 1.16.x before 1.16.5 has functions for DNS lookups that do not validate replies from DNS servers, which can lead to unsafe injections like XSS attacks.

Understanding CVE-2021-33195

This CVE highlights a vulnerability in Go versions prior to 1.15.13 and 1.16.x before 1.16.5 related to DNS lookup functions that do not properly validate server replies.

What is CVE-2021-33195?

The vulnerability in CVE-2021-33195 arises from Go's DNS lookup functions failing to validate DNS server responses, potentially allowing for unsafe injections such as cross-site scripting (XSS) attacks.

The Impact of CVE-2021-33195

This vulnerability could enable malicious actors to inject harmful code into DNS server replies, leading to XSS attacks that may compromise the security and integrity of affected systems.

Technical Details of CVE-2021-33195

The technical details of CVE-2021-33195 involve the lack of validation in DNS lookup responses, creating a window for attackers to exploit the returned values.

Vulnerability Description

Go versions prior to 1.15.13 and 1.16.x before 1.16.5 are susceptible to DNS reply injections due to insufficient validation, opening the door to XSS vulnerabilities.

Affected Systems and Versions

Systems running Go versions earlier than 1.15.13 and 1.16.x before 1.16.5 are impacted by this vulnerability, potentially exposing them to XSS attacks.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending malicious DNS responses that contain unsafe injections, allowing them to execute XSS attacks on vulnerable systems.

Mitigation and Prevention

To address CVE-2021-33195, immediate action and long-term security measures are essential.

Immediate Steps to Take

Update Go to version 1.15.13 or 1.16.5 to mitigate the vulnerability.
Monitor DNS responses for any suspicious or unexpected content.

Long-Term Security Practices

Implement input validation for DNS responses to prevent injection attacks.
Regularly update and patch Go installations to address security vulnerabilities.

Patching and Updates

Stay informed about security advisories and patches released by Go maintainers to safeguard your systems from potential exploits.