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Traffic ServerApplication · Apache

CVE-2018-11783

HIGH · 7.5 CVSS v3.0 Published 2019-03-07
Fix available
A fix is available. Upgrade to after 8.0.1 or later.
See remediation →
84/100
Remediation priority · High
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
sslheaders plugin extracts information from the client certificate and sets headers in the request based on the configuration of the plugin. The plugin doesn't strip the headers from the request in some scenarios. This problem was discovered in versions 6.0.0 to 6.0.3, 7.0.0 to 7.1.5, and 8.0.0 to 8.0.1.

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

The sslheaders plugin extracts client certificate information and sets headers in HTTP requests based on plugin configuration. In affected versions (6.0.0-6.0.3, 7.0.0-7.1.5, 8.0.0-8.0.1), the plugin fails to strip these sensitive certificate-derived headers in certain scenarios, potentially exposing confidential TLS client certificate data to backend servers or intermediate components.

MitigationUpgrade sslheaders to version 6.0.4, 7.1.6, 8.0.2 or later to receive the patch, and audit configurations to ensure certificate-derived headers are properly stripped in all request paths.

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
Traffic ServerApplication
Affected:>= 6.0.0, <= 6.0.3>= 7.0.0, <= 7.1.5>= 8.0.0, <= 8.0.1

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

CVSS:3.0/AV:N/AC:L/PR:N/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 Apache Traffic Server version
    Run 'traffic_server -V' or check the installed package version via package manager (e.g., 'rpm -q trafficserver' or 'dpkg -l trafficserver')
    Affected if The version number falls within 6.0.0-6.0.3, 7.0.0-7.1.5, or 8.0.0-8.0.1
  2. Verify sslheaders plugin is loaded
    Check plugin configuration in 'plugin.config' or 'records.config' for sslheaders entries, or list loaded plugins via 'traffic_server -K'
    Affected if The sslheaders plugin is loaded and active
  3. Inspect sslheaders plugin configuration
    Examine the sslheaders configuration file (commonly in /etc/trafficserver/ or specified in plugin.config) for directives that extract client certificate fields such as 'ssl-client-cert', 'ssl-client-subject', or similar certificate-derived header definitions
    Affected if The configuration contains directives that set certificate-derived headers (e.g., 'X-SSL-Client-Cert', 'X-Client-Cert', etc.) without corresponding stripping rules
  4. Check for header stripping configuration
    Review sslheaders config for any 'remove' or 'strip' directives applied to the certificate-derived headers in the request path
    Affected if There are no remove/strip directives for the certificate-derived headers, or the stripping is only applied in limited scenarios rather than all request paths

You are affected if your Apache Traffic Server version is vulnerable (6.0.0-6.0.3, 7.0.0-7.1.5, or 8.0.0-8.0.1) AND the sslheaders plugin is enabled with client certificate header extraction configured but without proper header stripping in all request paths.

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 a release after 8.0.1
Interim mitigation

Upgrade sslheaders to version 6.0.4, 7.1.6, 8.0.2 or later to receive the patch, and audit configurations to ensure certificate-derived headers are properly stripped in all request paths.

Fix this in Traffic Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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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-2018-11783 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