dbcve.org
CollaborationApplication · Zimbra

CVE-2023-26562

MEDIUM · 6.5 CVSS v3.1 Published 2024-02-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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
In Zimbra Collaboration (ZCS) 8.8.15 and 9.0, a closed account (with 2FA and generated passwords) can send e-mail messages when configured for Imap/smtp.

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

A logic bypass vulnerability in Zimbra Collaboration Suite where closed or disabled accounts that have 2FA enabled and use application-specific generated passwords can still authenticate via IMAP/SMTP and send email, bypassing account suspension/disablement controls.

MitigationEnsure closed/disabled accounts cannot authenticate regardless of 2FA status or application-specific passwords; apply vendor patches for ZCS 8.8.15 and 9.0; audit active IMAP/SMTP configurations for disabled accounts.

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

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. Check Zimbra Collaboration version
    Run 'zmcontrol -v' or check '/opt/zimbra/.gitdescribe' to identify the installed ZCS version
    Affected if Version is 8.8.15 or 9.0.0 (exact versions match)
  2. Identify disabled or closed accounts
    Run 'zmprov -l sa zimbraAccountStatus=closed' or query active directory/LDAP for accounts with status=disabled or closed
    Affected if Any accounts exist with closed or disabled status
  3. List application-specific passwords for disabled accounts
    Run 'zmprov -l getAccount <account> zimbraPasswordHistory' or query LDAP for accounts with zimbraCredentialVersion=2 (application-specific passwords) combined with closed/disabled status
    Affected if Disabled accounts have application-specific passwords configured
  4. Check 2FA/MFA status on disabled accounts
    Run 'zmprov -l getAccount <account> zimbraMfaCredentialStatus' or check LDAP for zimbraMfaEnabled=TRUE on closed accounts
    Affected if Disabled accounts have 2FA (MFA) enabled
  5. Verify IMAP/SMTP access for disabled accounts
    Attempt IMAP (port 993) or SMTP authentication using a disabled account's application-specific password
    Affected if Authentication succeeds when it should fail for a closed/disabled account

A user is affected if running ZCS 8.8.15 or 9.0.0 and any closed/disabled accounts with 2FA enabled and application-specific passwords can still authenticate via IMAP or SMTP.

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

Ensure closed/disabled accounts cannot authenticate regardless of 2FA status or application-specific passwords; apply vendor patches for ZCS 8.8.15 and 9.0; audit active IMAP/SMTP configurations for disabled accounts.

Fix this in Collaboration Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,544.

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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-2023-26562 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