CollaborationApplication · Zimbra

CVE-2020-35123

MEDIUM · 6.5 CVSS v3.1 Published 2020-12-17
Fix available
A fix is available. Upgrade to 8.8.15 or later.
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 Suite Network Edition versions < 9.0.0 P10 and 8.8.15 P17, there exists an XXE vulnerability in the saml consumer store extension, which is vulnerable to XXE attacks. This has been fixed in Zimbra Collaboration Suite Network edition 9.0.0 Patch 10 and 8.8.15 Patch 17.

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 · high confidence

Zimbra Collaboration Suite Network Edition contains an XML External Entity (XXE) vulnerability in the SAML consumer store extension. The vulnerability allows attackers to inject malicious XML entities into SAML authentication requests, potentially enabling disclosure of sensitive files or server-side request forgery. The flaw exists in versions prior to 9.0.0 Patch 10 and 8.8.15 Patch 17.

MitigationApply the vendor-supplied patches (ZCS 9.0.0 P10 or 8.8.15 P17) to remediate this vulnerability. If immediate patching is not possible, consider restricting access to the SAML consumer endpoint or disabling SAML authentication until the patch can be applied.

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:> 8.8.0, < 8.8.15= 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
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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. Identify Zimbra installation and version
    Run 'zmcontrol -v' or 'zmcontrol status' from the /opt/zimbra directory to retrieve the installed ZCS version
    Affected if Version is 8.8.1 through 8.8.15 (any patch), or 9.0.0 (any patch before P10)
  2. Confirm exact patch level
    Check the localconfig.xml file at /opt/zimbra/conf/localconfig.xml for the 'zimbra_version' or 'patch_version' attribute, or run 'zmcontrol -v' which displays the full version and patch level
    Affected if Version shows 9.0.0 without Patch 10, or 8.8.15 without Patch 17, or falls in the 8.8.1-8.8.14 range
  3. Determine if SAML authentication is enabled
    Review the Zimbra admin console for SAML/SSO configuration, or inspect the ZCS configuration files in /opt/zimbra/java/usr/share/tomcat/webapps/ for SAML-related XML configuration files under the web.xml or associated SAML consumer directories
    Affected if SAML authentication is configured or the SAML consumer store extension is present in the ZCS environment
  4. Verify SAML consumer store extension presence
    Inspect the /opt/zimbra directory for the SAML consumer store extension JAR files or configuration, typically found within the Jetty or Tomcat webapp directories used by ZCS
    Affected if The SAML consumer store extension is installed as part of the ZCS Network Edition installation

A ZCS installation is affected if it runs version 8.8.1 through 8.8.15 or version 9.0.0 prior to Patch 10, and has SAML authentication or the SAML consumer store extension enabled.

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
Upgrade available Upgrade to 8.8.15 or later
Fixed in 8.8.15
Interim mitigation

Apply the vendor-supplied patches (ZCS 9.0.0 P10 or 8.8.15 P17) to remediate this vulnerability. If immediate patching is not possible, consider restricting access to the SAML consumer endpoint or disabling SAML authentication until the patch can be applied.

Fix this in Collaboration Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2020-35123 in production — separate from our analysis above.

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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