CVE-2022-24682
KEVRansomware UseSynacor Zimbra Collaborate Suite (ZCS) Cross-Site Scripting Vulnerability
Description
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability in the Calendar feature that allows an attacker to execute arbitrary code.
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.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NPublishedFeb 9, 2022
Last modifiedAug 7, 2026
Added to KEVFeb 25, 2022
Remediation dueMar 11, 2022
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_CenterVendor Advisory
- wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P30Release NotesVendor Advisory
- wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory
- volexity.com/blog/2022/02/03/operation-emailthief-active-exploitation-of-zero-day-xss-vulnerability-in-zimbra/ExploitThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-24682US Government Resource
0 recent articles mention this CVE
74
Risk assessment · High
Actively exploited and used by ransomware crews. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1690 days
- Ransomware
- Used in known ransomware campaigns
- CVSS
- 6.1 MEDIUM
- EPSS (30-day exploit probability)
- 30.9% · top 2% of all CVEs
- Weakness
- CWE-116
- Attack vector
- Network, remotely reachable
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
- 5.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.