#VU55396 Cross-site scripting in Zimbra Collaboration - CVE-2021-35207

Vulnerability identifier: #VU55396

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-35207

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Zimbra Collaboration
Web applications / Webmail solutions

Vendor: Synacor Inc.

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data in the login component. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Zimbra Collaboration: 8.8.0 - 9.0.0

---

External links
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P23
https://wiki.zimbra.com/wiki/Security_Center
https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P16

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.