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

References

• GHSA-68xg-gqqm-vgj8
• puma/puma@690155e
• puma/puma@ed0f2f9
• https://github.com/puma/puma/releases/tag/v5.6.7
• https://github.com/puma/puma/releases/tag/v6.3.1
• https://nvd.nist.gov/vuln/detail/CVE-2023-40175
• puma/puma@7405a21
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/puma/CVE-2023-40175.yml