CVE-2021-34807 json
An open redirect vulnerability exists in the /preauth Servlet in Zimbra Collaboration Suite through 9.0.
published 2021-07-02 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21454
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 62%
- public exploits
- 0
- none known
Summary
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).
Patch / fix
- zimbra collaboration 8.8.15
Exploit prediction
0.98% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 5.8 | AV:N/AC:M/Au:N/C:P/I:P/A:N |
Classification
- Weakness
-
- CWE-601 URL Redirection to Untrusted Site
References
-
wiki.zimbra.com
/wiki/Zimbra_Security_Advisories
vendor-advisory
-
wiki.zimbra.com
/wiki/Security_Center
release-notes, vendor-advisory
-
wiki.zimbra.com
/wiki/Zimbra_Releases/9.0.0/P16
release-notes, vendor-advisory
-
wiki.zimbra.com
/wiki/Zimbra_Releases/8.8.15/P23
release-notes, vendor-advisory
Sources
- CVE List CVE-2021-34807
- NVD CVE-2021-34807
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