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CVE Record

CVE-2018-7159: The HTTP parser in all current versions of Node.js ignores spaces in the `Content-Length` header, allowing...

The HTTP parser in all current versions of Node.js ignores spaces in the `Content-Length` header, allowing input such as `Content-Length: 1 2` to be interpreted as having a value of `12`. The HTTP specification does not allow for spaces in the `Content-Length` value and the Node.js HTTP parser has been brought into line on this particular difference. The security risk of this flaw to Node.js users is considered to be VERY LOW as it is difficult, and may be impossible, to craft an attack that makes use of this flaw in a way that could not already be achieved by supplying an incorrect value for `Content-Length`. Vulnerabilities may exist in user-code that make incorrect assumptions about the potential accuracy of this value compared to the actual length of the data supplied. Node.js users crafting lower-level HTTP utilities are advised to re-check the length of any input supplied after parsing is complete.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

CVE-2018-7159 is a Node.js HTTP parsing inconsistency where spaces inside a Content-Length value were ignored. Node.js rated the security risk as very low, because useful attacks are difficult and may be impossible. The practical concern is custom low-level HTTP code that trusts parsed lengths too strongly.

Executive priority

Treat this as low urgency unless legacy Node.js or custom HTTP framing code is business-critical. Fold remediation into legacy runtime reduction and vendor patch governance rather than emergency response.

Technical view

Affected Node.js 4.x, 6.x, 8.x, and 9.x HTTP parsers accepted invalid Content-Length formatting by removing spaces before interpretation. This behavior differed from the HTTP specification. Risk is mainly in user code or infrastructure that makes incorrect assumptions about parsed body length versus actual received data.

Likely exposure

Exposure is most likely in legacy Node.js services, embedded products, or appliances still using affected Node.js branches. Risk is higher for custom HTTP parsing utilities or middleware handling raw request framing.

Exploitation context

The source bundle does not show active exploitation, and the CVE is not in CISA KEV. Node.js described practical exploitation as difficult and possibly impossible beyond already incorrect Content-Length handling.

Researcher notes

Focus analysis on parser normalization boundaries and downstream code assumptions. Evidence supports a standards-compliance bug with low standalone impact, not proven active exploitation. Avoid overstating request smuggling or desynchronization without environment-specific proof.

Mitigation direction

  • Identify any Node.js 4.x, 6.x, 8.x, or 9.x runtimes.
  • Apply vendor-supported Node.js security release guidance for affected deployments.
  • Review Red Hat or F5 advisories if their packaged products are involved.
  • Re-check request body length after parsing in low-level HTTP utilities.
  • Retire unsupported legacy Node.js branches where feasible.

Validation and detection

  • Inventory runtime versions across applications, containers, appliances, and vendor packages.
  • Review custom HTTP code for assumptions that parsed Content-Length is authoritative.
  • Confirm vendor advisories apply to any Red Hat or F5-managed components.
  • Verify updated parsers reject invalid Content-Length formatting according to vendor guidance.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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cwe · low confidence lookup

CWE-115: Exact CWE lookup

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CVE-2018-7159 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
The Node.js ProjectNode.js4.x, 6.x, 8.x, 9.xListed
Weakness

CWE details

CWE-115

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CWE-115 · source CWE mapping

Misinterpretation of Input

Misinterpretation of Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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