Cyber Resilience

CVE-2022-27924

Synacor Zimbra Collaboration Suite 8.8.15 … 9.0.0

CISA KEVActive ExploitationEUVD ExploitedRansomware-linked
Published
21 April 2022
Modified
04 August 2026
KEV Added
04 August 2022
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.85 99.7th percentile
Risk Priority 84 floored blend · peak EPSS

Summary

CVE-2022-27924 is a high-severity Injection (CWE-74) vulnerability in Synacor Zimbra Collaboration Suite. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Zimbra Collaboration (ZCS) versions 8.8.15 and 9.0 contain a vulnerability that permits injection of arbitrary memcache commands. The flaw stems from insufficient escaping of these commands, which allows an attacker to overwrite arbitrary entries in the cache and produces a CVSS 3.1 score of 7.5 under CWE-74.

An unauthenticated remote attacker can send crafted requests that reach the memcache layer directly. Successful exploitation results in modification of cached data without any authentication or user interaction, affecting the integrity of the targeted Zimbra instance.

Zimbra has published security advisories and patched releases, including 9.0.0 P24, on its official wiki pages that detail the affected components and available updates. The current EPSS score of 0.9070 with a recorded peak of 0.9195 indicates sustained exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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.

CWE(s)
KEV Date Added
04 August 2022

Related Threats

Threat-Actor AttributionAI

Cl0p
CISA KEV lists CVE-2022-27924 as ransomware-used; public reporting (Mandiant, Unit 42) attributes mass exploitation of this Zimbra memcache flaw to Cl0p/TA505 campaigns.

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1221 Template Injection Stealth
Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts.
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
T1674 Input Injection Execution
Adversaries may simulate keystrokes on a victim’s computer by various means to perform any type of action on behalf of the user, such as launching the command interpreter using keyboard shortcuts, typing an inline script to be executed,…
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-20281Shared CWE-74both on KEV
CVE-2019-2725Shared CWE-74both on KEV
CVE-2023-22527Shared CWE-74both on KEV
CVE-2020-8468Shared CWE-74both on KEV
CVE-2020-17496Shared CWE-74both on KEV
CVE-2019-11581Shared CWE-74both on KEV
CVE-2019-17558Shared CWE-74both on KEV
CVE-2025-20337Shared CWE-74both on KEV
CVE-2013-2251Shared CWE-74both on KEV
CVE-2022-35914Shared CWE-74both on KEV

Affected Assets

synacor
zimbra collaboration suite
8.8.15, 9.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.1
  • V1.2.3
  • V1.2.5
  • V1.2.8

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-74

Developer assessments and testing (including injection-focused techniques) identify improper neutralization of special elements, and the verifiable flaw remediation corrects them pre-deployment.

addresses: CWE-74

Identifies indicators of injection attacks (command, SQL, LDAP, etc.) via anomaly and attack monitoring.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and output encoding that prevent injection flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development catches injection vulnerabilities before release.

A.8.15 Logging partial match
finds

Logging supports detection of injection attempts but does not prevent the weakness.

finds

Monitoring activities can identify active injection attacks after they occur.

prevents

Secure development life cycle mandates input validation and output encoding that directly prevent injection flaws.

prevents

Application security requirements explicitly call for controls against injection attacks in software design.

prevents

Secure architecture principles reduce injection surfaces but do not prescribe specific neutralization techniques.

References