HTTP Request Smuggling

Overview

meinheld is a High performance asynchronous Python WSGI Web Server

Affected versions of this package are vulnerable to HTTP Request Smuggling. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Content-Length and Transfer encoding header parsing.

It is possible conduct HTTP request smuggling attacks by sending the Content-Length header twice. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own. Furthermore, invalid Transfer Encoding headers were found to be parsed as valid which could be leveraged for CL:TE or TE:CL smuggling attacks.

Remediation

Upgrade meinheld to version 1.0.2 or higher.

References

• GitHub Changelog
• GitHub Commit 1
• GitHub Commit 2