CVE-2021-34807 : Vulnerability Insights and Analysis

An open redirect vulnerability exists in the /preauth Servlet in Zimbra Collaboration Suite through 9.0, allowing an attacker with a valid zimbra auth token or preauth token to redirect users to any URL.

Understanding CVE-2021-34807

This CVE highlights an open redirect vulnerability present in Zimbra Collaboration Suite that could be exploited by attackers with specific tokens.

What is CVE-2021-34807?

CVE-2021-34807 is an open redirect vulnerability in the /preauth Servlet of Zimbra Collaboration Suite up to version 9.0. Attackers can abuse this flaw to redirect users to malicious URLs.

The Impact of CVE-2021-34807

The vulnerability poses a moderate risk as it enables attackers to redirect users to phishing pages or malicious websites, potentially leading to further exploits.

Technical Details of CVE-2021-34807

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The flaw allows attackers with valid tokens to redirect users using isredirect=1&redirectURL= parameters in conjunction with token data.

Affected Systems and Versions

Zimbra Collaboration Suite versions up to 9.0 are affected by this vulnerability.

Exploitation Mechanism

To exploit CVE-2021-34807, attackers need to possess a valid zimbra auth token or a valid preauth token obtained through unauthorized means.

Mitigation and Prevention

Protecting against and preventing the exploitation of this vulnerability is crucial.

Immediate Steps to Take

Organizations should monitor for unusual redirection activities and immediately revoke any suspicious auth or preauth tokens.

Long-Term Security Practices

Implementing strict token management practices and conducting regular security audits can help prevent token abuse.

Patching and Updates

Users are advised to update Zimbra Collaboration Suite to the latest version to mitigate the open redirect vulnerability.