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Debian LinuxOperating system · Debian

CVE-2017-16852

HIGH · 8.1 CVSS v3.0 Published 2017-11-16
Fix available
A fix is available. Upgrade to 2.6.1 or later.
See remediation →
90/100
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
shibsp/metadata/DynamicMetadataProvider.cpp in the Dynamic MetadataProvider plugin in Shibboleth Service Provider before 2.6.1 fails to properly configure itself with the MetadataFilter plugins and does not perform critical security checks such as signature verification, enforcement of validity periods, and other checks specific to deployments, aka SSPCPP-763.

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

The Dynamic MetadataProvider plugin in Shibboleth Service Provider before 2.6.1 fails to properly apply MetadataFilter plugins, which bypasses critical security checks including signature verification and validity period enforcement. This means metadata is accepted without validating its cryptographic signatures or checking whether it has expired or is not yet valid.

MitigationUpgrade to Shibboleth SP version 2.6.1 or later, and verify that MetadataFilter plugins (specifically signature verification and validity filters) are properly configured and actively enforcing security checks on incoming metadata.

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
Debian LinuxOperating system
Affected:= 8.0= 9.0
Service ProviderApplication
Affected:< 2.6.1

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

CVSS:3.0/AV:N/AC:H/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 Shibboleth SP version
    Run: shibd -v or check package version (dpkg -l | grep shibboleth on Debian)
    Affected if Version is less than 2.6.1, or running on Debian 8.0 or 9.0 with Shibboleth SP installed
  2. Locate Shibboleth SP configuration file
    Find shibboleth2.xml (typically in /etc/shibboleth/ or the SP config directory)
    Affected if Configuration file exists and the SP is in use
  3. Check if Dynamic MetadataProvider is configured
    Search the config file for <Dynamic> metadata provider elements or dynamicMetadataProvider configuration
    Affected if A Dynamic MetadataProvider is explicitly configured and in use
  4. Verify MetadataFilter plugins are configured
    Look for <Signature> and <ValidUntil> or <NotBefore> filter elements within the MetadataProvider sections in shibboleth2.xml
    Affected if No MetadataFilter elements are present, or filters exist but are not applied to the Dynamic provider
  5. Confirm signature verification is actively enforced
    Examine if MetadataFilter with cryptographic signature verification is applied to the metadata source in use
    Affected if Metadata is consumed without valid signature verification filter applied, or filters are defined but bypassed for the Dynamic provider

A user is affected if running Shibboleth SP version below 2.6.1 (or on Debian 8.0/9.0) and using a Dynamic MetadataProvider without properly configured and enforced MetadataFilter plugins for signature verification and validity checking.

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 2.6.1 or later
Fixed in 2.6.1
Interim mitigation

Upgrade to Shibboleth SP version 2.6.1 or later, and verify that MetadataFilter plugins (specifically signature verification and validity filters) are properly configured and actively enforcing security checks on incoming metadata.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation3.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,100
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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-2017-16852 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