CVE-2023-54397

critical

Description

Tornado before 6.3.3 contains an HTTP request smuggling vulnerability due to improper parsing of Content-Length headers accepting non-standard characters. Attackers can send crafted HTTP requests with these characters to bypass proxy validation and smuggle requests when deployed behind certain proxies.

References

https://www.vulncheck.com/advisories/tornado-before-6.3.3-http-request-smuggling-via-content-length

https://github.com/tornadoweb/tornado/security/advisories/GHSA-qppv-j76h-2rpx

Details

Source: Mitre, NVD

Published: 2026-09-15

Updated: 2026-09-17

Risk Information

CVSS v2

Base Score: 6.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 7.5

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

Severity: High

CVSS v4

Base Score: 9

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:L/SI:H/SA:N

Severity: Critical

EPSS

EPSS: 0.00367