Clang ExtraApplication · Clang Extra Project

CVE-2016-10655

HIGH · 8.1 CVSS v3.0 Published 2018-06-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
The clang-extra module installs LLVM's clang-extra tools. clang-extra downloads binary resources over HTTP, which leaves it vulnerable to MITM attacks. It may be possible to cause remote code execution (RCE) by swapping out the requested resources with an attacker controlled copy if the attacker is on the network or positioned in between the user and the remote server.

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 clang-extra npm package downloads LLVM clang-extra tool binaries over insecure HTTP, allowing man-in-the-middle attackers to intercept and replace the binaries with malicious code, potentially achieving remote code execution on systems installing or updating this package.

MitigationReplace all HTTP download URLs with HTTPS equivalents and implement checksum verification for downloaded binaries to ensure integrity.

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
Clang ExtraApplication
Affected:all versions

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. Check if clang-extra npm package is installed
    Run 'npm list -g clang-extra' or check your project's package.json for the clang-extra dependency
    Affected if The package appears in installed npm packages or dependencies
  2. Inspect the package download mechanism
    Examine the package's install script or postinstall script: find the package location (npm root -g) and inspect the relevant JS files for download URLs
    Affected if The code contains HTTP (not HTTPS) URLs for downloading LLVM/clang binaries
  3. Verify download URL protocol
    Search the package source for URL strings: grep -r 'http://' within the package directory, specifically looking for binary download endpoints
    Affected if Any HTTP URLs are found pointing to LLVM/clang binary distributions
  4. Check npm registry configuration
    Review the package's .npmrc or configuration files in the package directory for download base URLs
    Affected if Configured download endpoints use http:// instead of https://

If the clang-extra npm package is installed and its binary download mechanism uses unencrypted HTTP URLs, the environment is vulnerable to man-in-the-middle attacks during package installation or updates.

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

Replace all HTTP download URLs with HTTPS equivalents and implement checksum verification for downloaded binaries to ensure integrity.

Fix this in Clang Extra Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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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-2016-10655 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
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