What’s Vulnerable › Vulnerabilities
CVE-2021-34807
- Severity: medium (CVSS 6.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.0% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-07-02 · updated 2026-06-17
- Weakness: CWE-601
Description
An open redirect vulnerability exists in the /preauth Servlet in Zimbra Collaboration Suite through 9.0. To exploit the vulnerability, an attacker would need to have obtained a valid zimbra auth token or a valid preauth token. Once the token is obtained, an attacker could redirect a user to any URL via isredirect=1&redirectURL= in conjunction with the token data (e.g., a valid authtoken= value).
Affected products
- Zimbra Collaboration: before 8.8.15; 8.8.15, 8.8.15-p1, 8.8.15-p10, 8.8.15-p11, 8.8.15-p12, 8.8.15-p13 (+33) — fixed in 8.8.15
How to fix
Upgrade to a fixed version: Zimbra Collaboration 8.8.15. Check the vendor advisory for mitigations.
References
- https://wiki.zimbra.com/wiki/Security_Center
- https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23
- https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
- https://wiki.zimbra.com/wiki/Security_Center
- https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23
- https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
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