CVE-2021-34807

high-risk

Published 2021-07-02

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).

Do I need to act?

0.84% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 6.1/10 Medium

NETWORK / LOW complexity

Affected Products (20)

Collaboration

Affected Vendors

Zimbra

References (8)

Release Notes https://wiki.zimbra.com/wiki/Security_Center

Release Notes https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23

Release Notes https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16

Vendor Advisory https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

Release Notes https://wiki.zimbra.com/wiki/Security_Center

Release Notes https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23

Release Notes https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16

Vendor Advisory https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

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high-risk

Severity 23/34 · High

Exploitability 3/34 · Minimal

Exposure 24/34 · High