CVE-2023-26433 : Security Advisory and Response

This CVE-2023-26433 was published by OX on June 20, 2023, highlighting a vulnerability in the OX App Suite related to processing IMAP "capabilities" responses. The issue could potentially lead to excessive resource usage and service unavailability if exploited by a malicious actor.

Understanding CVE-2023-26433

This section delves into the key aspects of CVE-2023-26433, shedding light on the vulnerability's nature, impact, and affected systems.

What is CVE-2023-26433?

The CVE-2023-26433 vulnerability in the OX App Suite arises during the processing of IMAP "capabilities" responses. Attackers with access to a rogue IMAP service could exploit this flaw by triggering requests that result in excessive resource consumption. To mitigate this risk, OX Software GmbH has limited accepted IMAP server responses to reasonable lengths.

The Impact of CVE-2023-26433

The impact of CVE-2023-26433 is categorized as medium severity, with a CVSS base score of 4.3. The vulnerability's attack complexity is rated as low, occurring over a network without the need for high privileges. While the confidentiality and integrity impacts are deemed none, the availability impact is rated as low.

Technical Details of CVE-2023-26433

In this section, we delve deeper into the technical aspects of CVE-2023-26433, including the vulnerability description, affected systems, and the exploitation mechanism.

Vulnerability Description

The vulnerability in the OX App Suite allows attackers to exploit the IMAP "capabilities" responses, leading to excessive resource usage and potential service unavailability. By limiting the accepted IMAP server responses to reasonable sizes, the risk of exploitation is mitigated.

Affected Systems and Versions

The affected product is the OX App Suite by OX Software GmbH, specifically versions less than or equal to 7.10.6-rev39 and 8.10. Users utilizing these versions are vulnerable to the CVE-2023-26433 exploit.

Exploitation Mechanism

The exploitation of CVE-2023-26433 involves an attacker with access to a rogue IMAP service triggering requests that exceed reasonable resource consumption limits. This leads to service unavailability and potential denial of service if not addressed promptly.

Mitigation and Prevention

To safeguard systems from the CVE-2023-26433 vulnerability, immediate steps should be taken, complemented by long-term security practices and timely patching and updates.

Immediate Steps to Take

Immediately limit external mail account processing of IMAP "capabilities" responses to plausible sizes to prevent resource exhaustion attacks. Implement monitoring mechanisms to detect unusual resource consumption patterns.

Long-Term Security Practices

Enforce strict input validation mechanisms across all system components to prevent uncontrolled resource consumption vulnerabilities. Regularly review and update security configurations to align with evolving threat landscapes.

Patching and Updates

Ensure that the OX App Suite is updated to versions that limit the accepted IMAP server responses to reasonable lengths. Regularly check for security advisories from OX Software GmbH and apply patches promptly to mitigate potential risks.