9.8

CVSS Score

3.1

-

CVSS Score

Basic Information

CVE ID

CVE-2023-40175

GHSA ID

GHSA-68xg-gqqm-vgj8

EPSS Score

0.59969%

CWE

CWE-444

Published

8/18/2023

Updated

11/9/2023

KEV Status

Technology

Ruby

Basic Information

CVE ID

GHSA ID

EPSS Score

CWE

Published

Updated

KEV Status

Technology

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CVE-2023-40175

CVE-2023-40175: Puma HTTP Request/Response Smuggling vulnerability

Impact

Prior to version 6.3.1, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies and zero-length Content-Length headers in a way that allowed HTTP request smuggling.

The following vulnerabilities are addressed by this advisory:

Incorrect parsing of trailing fields in chunked transfer encoding bodies
Parsing of blank/zero-length Content-Length headers

Patches

The vulnerability has been fixed in 6.3.1 and 5.6.7.

Workarounds

No known workarounds.

References

HTTP Request Smuggling

For more information

If you have any questions or comments about this advisory:

Open an issue in Puma See our security policy

(GitHub Advisory)

Miggo Vulnerability Database

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CVE-2023-40175

CVE-2023-40175:

9.8

CVSS Score

3.1

-

CVSS Score

Basic Information

CVE ID

CVE-2023-40175

GHSA ID

GHSA-68xg-gqqm-vgj8

EPSS Score

0.59969%

CWE

CWE-444

Published

8/18/2023

Updated

11/9/2023

KEV Status

Technology

Ruby

Basic Information

CVE ID

GHSA ID

EPSS Score

CWE

Published

Updated

KEV Status

Technology

Technical Details

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Package Name	Ecosystem	Vulnerable Versions	First Patched Version
puma	rubygems	< 5.6.7	5.6.7
puma	rubygems	>= 6.0.0, < 6.3.1	6.3.1

Technical Details

Vulnerability Intelligence
Miggo AI

Root Cause Analysis

The vulnerability stems from two key functions in Puma's HTTP parsing logic:

In setup_body, the Content-Length validation lacked an empty string check, allowing smuggling via malformed headers.
In decode_chunk, trailer handling after the final chunk could be exploited to append smuggled requests. The commit patches show explicit fixes for these issues - adding empty string validation in Content-Length checks and implementing trailer skipping logic in chunk processing. The added test cases (test_cl_empty_string and test_crlf_trailer_smuggle) directly validate these fixes, confirming these were the vulnerable functions.

Vulnerable functions

Only Mi**o us*rs **n s** t*is s**tion

WAF Protection Rules

WAF Rule

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Reasoning

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9.8

-

Basic Information

Basic Information

Concerned about an active attack path?

CVE-2023-40175: Puma HTTP Request/Response Smuggling vulnerability

Impact

Patches

Workarounds

References

For more information

CVE-2023-40175:

9.8

-

Basic Information

Basic Information

Technical Details

Technical Details

Vulnerability IntelligenceMiggo AI

Root Cause Analysis

Vulnerable functions

WAF Protection Rules

WAF Rule

Reasoning

Vulnerability IntelligenceMiggo AI

Vulnerability IntelligenceMiggo AI

Root Cause Analysis

Vulnerable functions

WAF Protection Rules

WAF Rule

Reasoning

Basic Information

Basic Information

9.8

9.8

Technical Details

CVE-2023-40175: Puma HTTP Request/Response Smuggling vulnerability

Impact

Patches

Workarounds

References

For more information

Vulnerability Intelligence
Miggo AI

Vulnerability Intelligence
Miggo AI

Vulnerability Intelligence
Miggo AI