CVE-2022-24801Network attack vector

Request smuggling via permissive HTTP parsing

Published Apr 4, 2022 · Updated Apr 23, 2025

HTTP request smuggling in Twisted before 22.4.0rc1 allows remote attackers to desynchronize HTTP/1.1 proxy chains via malformed requests. In twisted.web.http, numeric conversion accepted signed Content-Length and 0x-prefixed chunk sizes, while chunk extensions and header whitespace were insufficiently constrained. Exploitation requires the HTTP/1.1 server or proxy behind a different parser; disagreement can bypass proxy-enforced validation or access control.

CVSS severity8.1
High
EPSS probability2.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Twisted before 22.4.0rc1 allows remote attackers to desynchronize HTTP/1.1 proxy chains via malformed requests. In twisted.web.http, numeric conversion accepted signed Content-Length and 0x-prefixed chunk sizes, while chunk extensions and header whitespace were insufficiently constrained. Exploitation requires the HTTP/1.1 server or proxy behind a different parser; disagreement can bypass proxy-enforced validation or access control.

The record

CVE
CVE-2022-24801
Published
Apr 4, 2022
Updated
Apr 23, 2025
Vendor
Twisted
Product
Twisted
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 4, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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.

  1. Affected versionversion=<= 22.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Twisted · Twistedversion=<= 22.2.0

Published CVSS scores

8.1UbuntuCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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