CVE-2021-34807
An open redirect vulnerability exists in the /preauth Servlet in Zimbra Collaboration Suite...
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).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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).
- Record
CVE-2021-34807- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 5.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
CVE List No score
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).
- Record
CVE-2021-34807- Updated
- 2026-11-02
EUVDEUVD-2021-21454 No score
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).
- Record
EUVD-2021-21454- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-fqph-hqc3-qf26 No score
An open redirect vulnerability exists in the /preauth Servlet in Zimbra Collaboration Suite...
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).
- Record
GHSA-fqph-hqc3-qf26- Weakness
- CWE-601
- Updated
- 2026-11-02
OSV
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).
- Record
CVE-2021-34807- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34807 is a medium vulnerability (CVSS 6.1) in Zimbra Collaboration, published July 2, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.98%, the 62nd percentile. No source names a fixed version.