CVE-2021-34558 : Security Advisory and Response
Discover the impact of CVE-2021-34558, a vulnerability in the Go crypto/tls package up to version 1.16.5, enabling malicious TLS servers to cause panic in clients. Learn how to mitigate the risks.
The crypto/tls package of Go through version 1.16.5 is vulnerable to a flaw where it fails to properly match the type of public key in an X.509 certificate during RSA based key exchange. This could allow a malicious TLS server to trigger a panic in a TLS client.
Understanding CVE-2021-34558
This section provides insights into the nature and impact of CVE-2021-34558.
What is CVE-2021-34558?
The vulnerability in the crypto/tls package of Go versions up to 1.16.5 allows a malicious TLS server to induce a panic in a TLS client by not correctly verifying the type of public key in an X.509 certificate during an RSA based key exchange.
The Impact of CVE-2021-34558
The impact of this vulnerability is significant as it can be exploited by an attacker to cause a denial of service by crashing TLS clients.
Technical Details of CVE-2021-34558
In this section, we delve into the technical aspects of CVE-2021-34558.
Vulnerability Description
The vulnerability arises from the lack of proper validation of the public key type in an X.509 certificate during RSA key exchange, leading to a potential panic in TLS clients.
Affected Systems and Versions
All versions of the Go programming language up to version 1.16.5 are affected by this vulnerability.
Exploitation Mechanism
An attacker can exploit this vulnerability by setting up a malicious TLS server to serve a crafted X.509 certificate, causing a panic in TLS clients performing an RSA based key exchange.
Mitigation and Prevention
This section offers guidance on mitigating the risks associated with CVE-2021-34558.
Immediate Steps to Take
Users are advised to update their Go installations to version 1.16.6 or newer, where the vulnerability has been patched.
Long-Term Security Practices
It is crucial to ensure regular updates and security patches are applied to programming language libraries to prevent similar vulnerabilities in the future.
Patching and Updates
Stay informed about security advisories and promptly apply patches released by the Go programming language community to protect against potential exploits of CVE-2021-34558.