CVE-2022-24766: Insufficient Protection against HTTP Request Smuggling in mitmproxy
Impact
In mitmproxy 7.0.4 and below, a malicious client or server is able to perform HTTP request smuggling attacks through mitmproxy. This means that a malicious client/server could smuggle a request/response through mitmproxy as part of another request/response's HTTP message body. While mitmproxy would only see one request, the target server would see multiple requests. A smuggled request is still captured as part of another request's body, but it does not appear in the request list and does not go through the usual mitmproxy event hooks, where users may have implemented custom access control checks or input sanitization.
Unless you use mitmproxy to protect an HTTP/1 service, no action is required.
Patches
The vulnerability has been fixed in mitmproxy 8.0.0 and above.
Acknowledgements
We thank Zeyu Zhang (@zeyu2001) for responsibly disclosing this vulnerability to the mitmproxy team.
Timeline
- 2022-03-15: Received initial report. - 2022-03-15: Verified report and confirmed receipt. - 2022-03-16: Shared patch with researcher. - 2022-03-16: Received confirmation that patch is working. - 2022-03-19: Published patched release and advisory.
Other sources
mitmproxy is an interactive, SSL/TLS-capable intercepting proxy. In mitmproxy 7.0.4 and below, a malicious client or server is able to perform HTTP request smuggling attacks through mitmproxy. This means that a malicious client/server could smuggle a request/response through mitmproxy as part of another request/response's HTTP message body. While mitmproxy would only see one request, the target server would see multiple requests. A smuggled request is still captured as part of another request's body, but it does not appear in the request list and does not go through the usual mitmproxy event hooks, where users may have implemented custom access control checks or input sanitization. Unless mitmproxy is used to protect an HTTP/1 service, no action is required. The vulnerability has been fixed in mitmproxy 8.0.0 and above. There are currently no known workarounds.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2022-24766?
CVE-2022-24766 is a vulnerability in mitmproxy 7.0.4 and below that allows malicious clients or servers to perform HTTP request smuggling attacks.
How severe is CVE-2022-24766?
CVE-2022-24766 has a severity rating of 9.8 (Critical).
What is HTTP request smuggling?
HTTP request smuggling is a technique where an attacker manipulates the HTTP protocol to bypass security measures and perform malicious actions.
How can I fix CVE-2022-24766?
To fix CVE-2022-24766, upgrade to mitmproxy version 8.0.0 or newer.
Where can I find more information about CVE-2022-24766?
You can find more information about CVE-2022-24766 in the MITMProxy security advisory and the NVD website.