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Synacor · Zimbra Collaboration Suite (ZCS)

CVE-2022-27924

Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability

Exploited in attacks Used by ransomware Critical 9.8 Attack chance: 94%
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What it is

Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache commands into a targeted instance. These memcache commands becomes unescaped, causing an overwrite of arbitrary cached entries.

CISA: Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to inject memcache commands into a targeted instance which causes an overwrite of arbitrary cached entries.

What to do

Apply updates per vendor instructions.

Deadline for US federal agencies: August 25, 2022

Added to the CISA list
August 4, 2022
Published
April 20, 2022
Severity
Critical 9.8 CVSS 3.1
Chance of attacks in the next 30 days (EPSS)
94% in the top 0.2% of all known vulnerabilities
Weakness
CWE-93
More details
NVD · CVE.org · CISA
All references (3)

More exploited flaws from Synacor

AddedVulnerabilityProductSeverityAttack chance
Aug 21, 2026OS Command InjectionCVE-2026-73570Zimbra Collaboration Suite (ZCS)High 8.972%
Apr 20, 2026Cross-site ScriptingCVE-2025-48700Zimbra Collaboration Suite (ZCS)Medium 6.11.7%
Mar 18, 2026Cross-Site ScriptingCVE-2025-66376Zimbra Collaboration Suite (ZCS)High 7.220%
Oct 7, 2025Cross-site ScriptingCVE-2025-27915Zimbra Collaboration Suite (ZCS)Medium 5.44.1%
Jul 7, 2025Server-Side Request Forgery (SSRF)CVE-2019-9621Zimbra Collaboration Suite (ZCS)High 7.581%
May 19, 2025Cross-Site Scripting (XSS)CVE-2024-27443Zimbra Collaboration Suite (ZCS)Medium 6.125%
Feb 25, 2025Cross-Site Scripting (XSS)CVE-2023-34192Zimbra Collaboration Suite (ZCS)Critical 9.077%
Oct 3, 2024Command ExecutionCVE-2024-45519Zimbra Collaboration Suite (ZCS)Critical 10.099.9%

All of them →

Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.