CVE-2022-27924
CVE-2022-27924 — Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability
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.
Published Updated Sources: NVD, CISA, FIRST EPSS
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Confirmed
CISA KEV, listed Aug 4, 2022
EPSS
85%
ahead of 99.7% of scored CVEs
CVSS base
7.5
high · 2 sources
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
Active
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Remediation
The vendor's own words where we have them.
Upgrade Zimbra Collaboration Suite (ZCS) to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
CISA required action
Apply updates per vendor instructions.
Federal deadline Aug 25, 2022 — passed 1,481 days ago
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Treat as emergency remediation because CISA KEV status is present.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| Synacor | Zimbra Collaboration Suite (ZCS) | — | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
None
Confidentiality
None
Integrity
High
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Network
Privileges Req
None
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | high | 3.9 | 3.6 | NVD, CNA |
| 5 | CVSS 2.0 | medium | 10 | 2.9 | NVD |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness & attack patterns
- CWE-74Injection
Inferred from the weakness class — not observed against this CVE.
- T1562.003Impair Defenses: Impair Command History Logging
- T1574.006Hijack Execution Flow: Dynamic Linker Hijacking
- T1574.007Hijack Execution Flow: Path Interception by PATH Environment Variable
CISA KEV details
CISA lists a CVE here once it has evidence of exploitation against real targets.
Listed
Aug 4, 2022
Federal deadline
Aug 25, 2022
passed 1,481 days ago
Ransomware use
Known
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Prioritize edge telemetry for network-reachable Zimbra Collaboration Suite (ZCS).
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 7.5 (AV:N)
Jun 17, 2026 · NVD
- 2022
Added to CISA KEV catalog
Aug 4, 2022 · CISA
Initial · CVE published
Apr 21, 2022 · NVD
References
6 on the record
- wiki.zimbra.com/wiki/Security_Center
Vendor Advisory
- wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P24
Release Notes, Vendor Advisory
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories
Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-27924
US Government Resource
- wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P24.1#Security_Fixes
Vendor Advisory
- nvd.nist.gov/vuln/detail/CVE-2022-27924
Vendor Advisory
Elsewhere on this site
- Synacorevery CVE for this vendor
- August 2022what else CISA listed
- Injectionsame class
- CWE-74other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2022-27924 is Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability, a high vulnerability affecting Zimbra Collaboration Suite (ZCS) from Synacor. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2022-27924. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.5 describes technical severity, while EPSS 85% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.