Request smuggling via malformed Transfer-Encoding parsing
Published Feb 7, 2020 · Updated Apr 30, 2025
HTTP request smuggling in affected Node.js releases allows remote attackers to deliver malicious payloads via malformed Transfer-Encoding headers. The bundled HTTP parser fails to track arbitrary Transfer-Encoding values and reject unknown or nonterminal codings, allowing intermediaries and the server to disagree on message boundaries. Exploitation requires an HTTP server behind an intermediary that reuses connections and parses the crafted headers differently; consequences include session hijacking, cookie poisoning, and delivery of attacker-controlled follow-on requests.
Summary
What happened
HTTP request smuggling in affected Node.js releases allows remote attackers to deliver malicious payloads via malformed Transfer-Encoding headers. The bundled HTTP parser fails to track arbitrary Transfer-Encoding values and reject unknown or nonterminal codings, allowing intermediaries and the server to disagree on message boundaries. Exploitation requires an HTTP server behind an intermediary that reuses connections and parses the crafted headers differently; consequences include session hijacking, cookie poisoning, and delivery of attacker-controlled follow-on requests.
The record
- CVE
- CVE-2019-15605
- Published
- Feb 7, 2020
- Updated
- Apr 30, 2025
- Vendor
- Node.js
- Product
- Node.js
- Classifications
- CWE-444, CAPEC-33, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 7, 2020CVE publishedPublication date reported by the CVE source.
- Apr 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0 <10.19.0
- Affected versionversion=11.0 <11.*
- Affected versionversion=12.0 <12.15.0
- Affected versionversion=13.0 <13.8.0
- Affected versionversion=4.0 <4.*
- Affected versionversion=5.0 <5.*
- Affected versionversion=6.0 <6.*
- Affected versionversion=7.0 <7.*
- Affected versionversion=8.0 <8.*
- Affected versionversion=9.0 <9.*
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Backend HTTP Socket Poisoning PoCproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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