CVE-2023-38697Network attack vector

HTTP request smuggling via permissive framing parsing

Published Aug 4, 2023 · Updated Oct 4, 2024

HTTP request smuggling in Socketry Protocol::HTTP1 before 0.15.1 allows remote attackers to bypass intermediaries via malformed HTTP framing. Connection#extract_content_length accepted signed and hexadecimal values through permissive integer conversion, while the chunked-body reader accepted prefixed sizes and bare LF in extensions. Exploitation requires forwarding through multiple HTTP parsers that interpret the malformed framing differently, enabling request desynchronization and firewall bypass.

CVSS severity5.8
Medium
EPSS probability0.75%
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 Socketry Protocol::HTTP1 before 0.15.1 allows remote attackers to bypass intermediaries via malformed HTTP framing. Connection#extract_content_length accepted signed and hexadecimal values through permissive integer conversion, while the chunked-body reader accepted prefixed sizes and bare LF in extensions. Exploitation requires forwarding through multiple HTTP parsers that interpret the malformed framing differently, enabling request desynchronization and firewall bypass.

The record

CVE
CVE-2023-38697
Published
Aug 4, 2023
Updated
Oct 4, 2024
Vendor
Socketry
Product
Protocol::HTTP1
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 4, 2024Record 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=0 <0.15.1
  2. Affected versionversion=< 0.15.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Socketry · Protocol::HTTP1version=0 <0.15.1; version=< 0.15.1

Published CVSS scores

5.8GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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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