CVE-2021-29923 : Security Advisory and Response

Go before 1.17 does not properly consider extraneous zero characters at the beginning of an IP address octet, which allows attackers to bypass access control based on unexpected octal interpretation.

Understanding CVE-2021-29923

This CVE affects net.ParseIP and net.ParseCIDR in Go before version 1.17.

What is CVE-2021-29923?

CVE-2021-29923 highlights a vulnerability in Go programming language versions prior to 1.17. It arises from the improper handling of zero characters at the start of an IP address octet, leading to potential security bypass.

The Impact of CVE-2021-29923

The vulnerability could enable attackers to circumvent access controls that rely on IP addresses, posing a risk to the security and integrity of affected systems.

Technical Details of CVE-2021-29923

The following technical aspects are pertinent to understanding CVE-2021-29923:

Vulnerability Description

Go versions before 1.17 are susceptible to a flaw that allows attackers to exploit extraneous zero characters at the beginning of an IP address octet, impacting net.ParseIP and net.ParseCIDR functions.

Affected Systems and Versions

All systems using Go programming language versions prior to 1.17 are vulnerable to this security issue.

Exploitation Mechanism

Exploiting CVE-2021-29923 involves manipulating zero characters in an IP address octet to bypass IP-based access controls in certain scenarios.

Mitigation and Prevention

To address CVE-2021-29923, consider the following mitigation strategies:

Immediate Steps to Take

Update Go programming language to version 1.17 or newer.
Review and revise access control mechanisms that rely on IP addresses for increased security.

Long-Term Security Practices

Regularly monitor for security advisories and updates from Go and relevant vendors.
Conduct security assessments to identify and remedy similar vulnerabilities in the future.

Patching and Updates

Refer to the provided references for patches and updates regarding CVE-2021-29923.