CVE-2020-12398 : Security Advisory and Response

A security vulnerability in Thunderbird could lead to information leakage when using STARTTLS for an IMAP server.

Understanding CVE-2020-12398

If Thunderbird is configured to use STARTTLS for an IMAP server and receives a PREAUTH response, it may continue with an unencrypted connection, potentially exposing email data.

What is CVE-2020-12398?

This CVE describes a security downgrade issue in Thunderbird that could result in email data being sent without encryption, affecting versions prior to 68.9.0.

The Impact of CVE-2020-12398

The vulnerability could lead to information leakage due to the lack of encryption when Thunderbird encounters a PREAUTH response from an IMAP server.

Technical Details of CVE-2020-12398

A closer look at the technical aspects of this CVE.

Vulnerability Description

Thunderbird, when using STARTTLS for an IMAP server, may continue with an unencrypted connection after receiving a PREAUTH response.

Affected Systems and Versions

Product: Thunderbird
Vendor: Mozilla
Versions Affected: < 68.9.0

Exploitation Mechanism

An attacker could potentially intercept and view email data due to the lack of encryption in the connection.

Mitigation and Prevention

Steps to address and prevent the CVE-2020-12398 vulnerability.

Immediate Steps to Take

Update Thunderbird to version 68.9.0 or newer to mitigate the vulnerability.
Avoid using unsecured networks when accessing email accounts.

Long-Term Security Practices

Regularly update email clients and ensure encryption protocols are enforced.

Patching and Updates

Stay informed about security advisories from Mozilla and apply patches promptly to address known vulnerabilities.