Synacor Zimbra Collaborate Suite (ZCS) Cross-Site Scripting Vulnerability

MEDIO 6.1EXPLOITED (CISA KEV)CVE-2022-24682 · Published 09/02/2022 · updated 07/08/2026

Synacor Zimbra Collaborate Suite (ZCS) Cross-Site Scripting Vulnerability. Actively exploited: CISA added this vulnerability to its Known Exploited Vulnerabilities catalog on 25/02/2022. Patch affected systems as an emergency. It is known to be used in ransomware campaigns.

Package	Affected versions	Patched versions
zimbra collaboration suite synacor	`= 8.8.15≥ 8.8.0, < 8.8.15`	`8.8.15`

Description

An issue was discovered in the Calendar feature in Zimbra Collaboration Suite 8.8.x before 8.8.15 patch 30 (update 1), as exploited in the wild starting in December 2021. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.

References

blog.zimbra.com/2022/02/hotfix-available-5-feb-for-zero-day-exploit-vulnerability-in-zimbra-8-8-15 · Vendor Advisory
wiki.zimbra.com/wiki/Security_Center · Vendor Advisory
wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P30 · Release Notes
wiki.zimbra.com/wiki/Zimbra_Security_Advisories · Vendor Advisory
volexity.com/blog/2022/02/03/operation-emailthief-active-exploitation-of-zero-day-xss-vulnerability-in-zimbra · Exploit
cisa.gov/known-exploited-vulnerabilities-catalog · US Government Resource
CISA KEV · CVE-2022-24682

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