CVE-2021-36222 : Vulnerability Insights and Analysis

MIT Kerberos 5 (krb5) before 1.18.4 and 1.19.x before 1.19.2 is vulnerable to CVE-2021-36222. Attackers can exploit the

ec_verify

function in

kdc_preauth_ec.c

to trigger a NULL pointer dereference, leading to a daemon crash.

Understanding CVE-2021-36222

This section delves into the details of the CVE-2021-36222 vulnerability.

What is CVE-2021-36222?

The CVE-2021-36222 vulnerability exists in MIT Kerberos 5 (krb5) versions before 1.18.4 and 1.19.x before 1.19.2. It allows remote attackers to cause a NULL pointer dereference and subsequent daemon crash due to improper management of a return value in a specific scenario.

The Impact of CVE-2021-36222

Exploitation of this vulnerability can result in a denial of service (DoS) condition where an attacker could crash the daemon, leading to service disruption.

Technical Details of CVE-2021-36222

Let's explore the technical aspects of CVE-2021-36222 in detail.

Vulnerability Description

The vulnerability arises from the

ec_verify

function in

kdc_preauth_ec.c

, where a certain situation is not properly handled, allowing remote attackers to exploit it.

Affected Systems and Versions

MIT Kerberos 5 (krb5) versions before 1.18.4 and 1.19.x before 1.19.2 are affected by this CVE, making systems running these versions vulnerable to exploitation.

Exploitation Mechanism

Remote attackers can exploit this vulnerability by triggering a NULL pointer dereference through the

ec_verify

function, causing the daemon to crash.

Mitigation and Prevention

Discover how to protect your systems from CVE-2021-36222.

Immediate Steps to Take

Update MIT Kerberos 5 to versions 1.18.4 or 1.19.2 to patch the vulnerability.
Monitor network traffic for any suspicious activity that could indicate an ongoing attack.

Long-Term Security Practices

Regularly update and patch your systems' software to address known vulnerabilities promptly.
Implement strong access controls and authentication mechanisms to limit unauthorized access.

Patching and Updates

Stay informed about security advisories from MIT Kerberos, Debian, Oracle, and other relevant sources to deploy patches and updates as soon as they are available.