CVE-2023-4583 : Security Advisory and Response

This CVE record was assigned by Mozilla and was published on September 11, 2023. The vulnerability affects Firefox, Firefox ESR, and Thunderbird.

Understanding CVE-2023-4583

This CVE involves a vulnerability related to the Browsing Context not being properly cleared when closing a Private Window in Mozilla applications.

What is CVE-2023-4583?

The vulnerability in CVE-2023-4583 occurs when checking if the Browsing Context had been discarded in

HttpBaseChannel

. If the load group was not available, it was assumed to have been discarded, which was not always the case for private channels after the private session had ended. This issue affects Firefox versions less than 117, Firefox ESR versions less than 115.2, and Thunderbird versions less than 115.2.

The Impact of CVE-2023-4583

This vulnerability could potentially lead to the Browsing Context not being properly cleared when closing a Private Window, which may result in unauthorized access to sensitive information in the browser or email client.

Technical Details of CVE-2023-4583

This section provides more details about the vulnerability, including the description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The issue arises due to incorrect handling of the Browsing Context in

HttpBaseChannel

, leading to an incorrect assumption about the status of the load group, potentially exposing private channel data.

Affected Systems and Versions

Firefox < 117
Firefox ESR < 115.2
Thunderbird < 115.2

Exploitation Mechanism

Attackers can exploit this vulnerability by using a crafted webpage or email to trigger the incorrect handling of the Browsing Context, allowing them to access sensitive information.

Mitigation and Prevention

To address CVE-2023-4583, immediate steps should be taken to mitigate the risk and prevent potential exploitation.

Immediate Steps to Take

Users are advised to update their Firefox and Thunderbird applications to versions 117 and 115.2 or higher, respectively, to mitigate the vulnerability. Additionally, caution should be exercised when opening unknown links or emails to prevent exploitation.

Long-Term Security Practices

It is recommended to practice safe browsing habits, such as avoiding suspicious websites and links, keeping software up to date, and using strong, unique passwords to enhance overall cybersecurity.

Patching and Updates

Mozilla has released patches to address this vulnerability in Firefox and Thunderbird. Users are urged to apply these updates promptly to protect their systems from potential attacks.