#VU62356 Stored cross-site scripting in Zimbra Collaboration - CVE-2018-6882

Vulnerability identifier: #VU62356

Vulnerability risk: Medium

CVSSv4.0: 5.1 [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:A/U:Green]

CVE-ID: CVE-2018-6882

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Zimbra Collaboration
Web applications / Webmail solutions

Vendor: Synacor Inc.

Description

Vulnerability allows a remote attacker to perform Cross-site scripting attacks.

An input validation error exists in the ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS). A remote attacker can inject a specially crafted script into the Content-Location header in an email attachment and execute it when the attachment is opened.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Zimbra Collaboration: 8.6.0 Patch 1 - 8.8.6

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External links
https://seclists.org/fulldisclosure/2018/Mar/52
https://bugzilla.zimbra.com/show_bug.cgi?id=108786
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.7
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://www.securify.nl/advisory/SFY20180101/cross-site-scripting-vulnerability-in-zimbra-collaboration-suite-due-to-the-way-it-handles-attachment-links.html

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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?

Yes. This vulnerability is being exploited in the wild.