dbcve.org
Debian LinuxOperating system · Debian

CVE-2018-0486

MEDIUM · 6.5 CVSS v3.0 Published 2018-01-13
Fix available
A fix is available. Upgrade to 1.6.3 or later.
See remediation →
74/100
Remediation priority · Elevated
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
Shibboleth XMLTooling-C before 1.6.3, as used in Shibboleth Service Provider before 2.6.0 on Windows and other products, mishandles digital signatures of user attribute data, which allows remote attackers to obtain sensitive information or conduct impersonation attacks via a crafted DTD.

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 vulnerability exists in XMLTooling-C's XML digital signature validation. When processing SAML attribute data containing DTD (Document Type Definition) entities, the signature verification can be bypassed or circumvented. Attackers can craft malicious DTD to manipulate signed XML content, allowing them to forge attribute assertions and impersonate users.

MitigationUpgrade XMLTooling-C to version 1.6.3 or later and Shibboleth Service Provider to version 2.6.0 or later. After upgrading, verify that SAML attribute signing and validation continue to function correctly.

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:= 7.0= 8.0= 9.0
Xmltooling CApplication
Affected:< 1.6.3

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
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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 if XMLTooling-C is installed
    Run 'dpkg -l | grep xmltooling' on Debian systems, or check for libraries named xmltooling in /usr/lib/, or run 'xmltooling-c --version' if the command is available
    Affected if XMLTooling-C package or library is present on the system
  2. Determine the installed version of XMLTooling-C
    Use package manager: 'dpkg -l libxmltooling*' on Debian, or check the library file version with 'strings /usr/lib/libxmltooling.so | grep -i version'
    Affected if Version is lower than 1.6.3 or cannot be determined to be 1.6.3 or higher
  3. Check if SAML Service Provider component is present
    Look for shibd service or shibboleth SP configuration files in /etc/shibboleth/ or check for 'shibd' process running
    Affected if Shibboleth Service Provider using XMLTooling-C for SAML attribute processing is installed
  4. Inspect XMLTooling-C configuration for DTD handling
    Review /etc/xmltooling/xmltooling.xml or /etc/shibboleth/shibboleth2.xml for XML parser configuration. Look for settings controlling external entity processing or DTD validation
    Affected if XML parser is configured to allow external DTD entities in SAML attribute assertions without strict validation disabled
  5. Verify if attribute processing handles unsigned or loosely validated XML
    Check SAML attribute handler configuration in /etc/shibboleth/attribute-map.xml or similar, and review logs for SAML attribute assertions being processed
    Affected if SAML attribute assertions with embedded DTD entities are being processed and the signature validation relies on XMLTooling-C

The environment is affected if XMLTooling-C version is below 1.6.3 and SAML attribute assertions containing DTD entities are being processed with signature validation performed by the vulnerable library.

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 1.6.3 or later
Fixed in 1.6.3
Interim mitigation

Upgrade XMLTooling-C to version 1.6.3 or later and Shibboleth Service Provider to version 2.6.0 or later. After upgrading, verify that SAML attribute signing and validation continue to function correctly.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,416.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-0486 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2018-0486 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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