Cyber Resilience

CVE-2021-39214

High

Published: 16 September 2021

Published
16 September 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0019 41.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-39214 is a high-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Mitmproxy Mitmproxy. Its CVSS base score is 8.1 (High).

Operationally, ranked at the 41.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

mitmproxy is an interactive, SSL/TLS-capable intercepting proxy. In mitmproxy 7.0.2 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…

more

part of another request/response's HTTP message body. While a smuggled request is still captured as part of another request's body, 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 one uses mitmproxy to protect an HTTP/1 service, no action is required. The vulnerability has been fixed in mitmproxy 7.0.3 and above.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mitmproxy
mitmproxy
≤ 7.0.2

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References