CVE-2023-3326 Explained : Impact and Mitigation

This CVE, assigned by freebsd, was published on June 22, 2023, affecting FreeBSD systems. It involves a network authentication attack via pam_krb5, potentially allowing unauthorized authentication for any user on the system.

Understanding CVE-2023-3326

This vulnerability in FreeBSD's pam_krb5 module can be exploited if certain conditions are met, leading to authentication abuse. Understanding the impact and technical details is crucial for mitigating the risk effectively.

What is CVE-2023-3326?

The vulnerability involves pam_krb5 authentication, where the system may trust invalid responses from the Kerberos KDC, potentially allowing an attacker to authenticate as any user without proper validation.

The Impact of CVE-2023-3326

This CVE poses a significant risk of authentication abuse, potentially granting unauthorized access to sensitive systems and data. It falls under CAPEC-114, highlighting the severity of the issue.

Technical Details of CVE-2023-3326

To address this vulnerability effectively, understanding its technical aspects is essential.

Vulnerability Description

pam_krb5 authenticates users by obtaining a ticket-granting ticket from the Kerberos KDC. Without proper keytab provisioning, it can trust potentially invalid responses, enabling unauthorized authentication.

Affected Systems and Versions

Systems running FreeBSD versions 12.4-RELEASE, 13.1-RELEASE, and 13.2-RELEASE are affected if pam_krb5 is enabled without a keytab provision.

Exploitation Mechanism

An attacker controlling password and KDC responses can exploit this vulnerability in non-default FreeBSD configurations leveraging pam_krb5 without a keytab.

Mitigation and Prevention

Taking immediate steps and implementing long-term security practices are crucial to mitigate the risk posed by CVE-2023-3326.

Immediate Steps to Take

If not using Kerberos, ensure /etc/krb5.conf is missing.
Comment out pam_krb5 in PAM configuration if not in use.
Ensure keytab provision if using pam_krb5 for authentication.

Long-Term Security Practices

Regularly review and update PAM configurations. Implement strong authentication mechanisms and key management practices. Monitor for any suspicious authentication activities.

Patching and Updates

Stay informed about security advisories and patch your FreeBSD systems promptly to address CVE-2023-3326. Continuously monitor for any changes in the FreeBSD-SA-23:04.pam_krb5 advisory and follow the recommended actions to secure your systems.