Exploited· due 2022-05-106.1mediumMediumused in ransomware

CVE-2018-6882

Synacor Zimbra Collaboration Suite

Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS) before 8.7 Patch 1 and 8.8.x before 8.8.7 might allow remote attackers to inject arbitrary web script or HTML via a Content-Location header in an email attachment.

Exploitation status

CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
It is known to have been used in ransomware campaigns.
US federal civilian agencies are required to remediate it by 2022-05-10. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.
A vendor advisory or patch reference has been published.

Required action

Apply updates per vendor instructions.

CISA’s wording, unedited.

What the metrics mean

It is reachable over a network, without needing local access.
For an attacker who can reach it, no special conditions are needed to exploit it.
To exploit it, no account is needed.
Beyond that, someone has to be persuaded to take an action first.

Scoring

CVSS: 6.1 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Assigned by: cve@mitre.org

Dates

Published: 2018-03-27
Last modified: 2026-08-13
Added to KEV: 2022-04-19
Remediation due: 2022-05-10
Sources: CISA KEV, NVD

Affected products

Synacor Zimbra Collaboration Suite- 8.7.0, 8.7.0, 8.8.0, 8.8.1, 8.8.2, 8.8.3, 8.8.4, 8.8.5, 8.8.6

As listed in the NVD configuration data. Not a statement about your estate.