Inconsistent interpretation of HTTP requests in Tornado - #VU128146
Published: August 12, 2023 / Updated: April 27, 2026
Vulnerability identifier: #VU128146
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Tornado
Tornado
Software vendor:
Tornado
Tornado
Description
The vulnerability allows a remote attacker to perform HTTP request smuggling.
The vulnerability exists due to inconsistent interpretation of HTTP requests in tornado/http1connection.py when parsing Content-Length fields and chunk lengths containing non-standard characters. A remote attacker can send a specially crafted request to perform HTTP request smuggling.
Exploitation requires Tornado to be deployed behind certain proxies that interpret those non-standard characters differently.
Remediation
Install security update from vendor's website.