CollaborationApplication · Zimbra

CVE-2023-29381

CRITICAL · 9.8 CVSS v3.1 Published 2023-07-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue in Zimbra Collaboration (ZCS) v.8.8.15 and v.9.0 allows a remote attacker to escalate privileges and obtain sensitive information via the password and 2FA parameters.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Zimbra Collaboration Suite versions 8.8.15 and 9.0 contain a critical authentication flaw where a remote attacker can manipulate password and 2FA parameters to escalate privileges and access sensitive information. The vulnerability enables unauthorized access by bypassing or manipulating the authentication mechanism.

MitigationApply vendor-supplied patches or upgrade to a fixed ZCS version that addresses this authentication/authorization flaw; verify that both password-based and 2FA authentication flows properly enforce access controls post-patch.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CollaborationApplication
Affected:= 8.8.15= 9.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed ZCS version
    Run 'zmcontrol -v' or 'zimbractl -v' from the Zimbra server command line to retrieve the exact Zimbra Collaboration Suite version number
    Affected if The version displayed is exactly 8.8.15 or exactly 9.0.0 (note the '=' in the affected version range indicates these exact versions)
  2. Verify authentication module configuration
    Check the Zimbra authentication configuration by examining /opt/zimbra/jetty/webapps/zimbra/WEB-INF/web.xml or running 'zmprov getConfig zimbraAuthEnabled' to confirm authentication mechanisms are properly configured
    Affected if Authentication is enabled but the version is vulnerable (8.8.15 or 9.0.0)
  3. Review admin console access logs
    Examine Zimbra access logs in /opt/zimbra/log/audit.log and /opt/zimbra/log/zmsetup.log for unusual authentication patterns, failed login attempts, or privilege escalation indicators around password and 2FA operations
    Affected if Logs show authentication anomalies or unauthorized privilege escalation attempts in the affected version
  4. Check 2FA configuration settings
    Run 'zmprov getAccount <account> zimbraTwoFactorAuthEnabled' on selected accounts or check /opt/zimbra/conf/localconfig.xml for two-factor authentication enforcement settings
    Affected if 2FA is configured on systems running the affected versions and may be bypassed
  5. Audit admin accounts and delegated admin roles
    Review admin accounts via 'zmprov -l gaaa' and check /opt/zimbra/conf/attrs/ldapattrs.xml for any unexpected privilege grants or role modifications that could indicate exploitation
    Affected if Unexpected admin accounts or privilege modifications exist on vulnerable versions

A system is affected if it runs exactly ZCS version 8.8.15 or exactly 9.0.0 and relies on password-based or 2FA authentication, as these versions contain the authentication bypass flaw.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-supplied patches or upgrade to a fixed ZCS version that addresses this authentication/authorization flaw; verify that both password-based and 2FA authentication flows properly enforce access controls post-patch.

Fix this in Collaboration Scoped from the published advisory
  • Consultation8.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA6.0 h
36.0 hours of engineering $6,340
Get help mitigating

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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-29381 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data