CVE-2022-3215: NIOHTTP1 and projects using it for generating HTTP responses can be subject to a HTTP Response Injection attack. This occurs when a HTTP/1.1 server ac...

Description

NIOHTTP1 and projects using it for generating HTTP responses can be subject to a HTTP Response Injection attack. This occurs when a HTTP/1.1 server accepts user generated input from an incoming request and reflects it into a HTTP/1.1 response header in some form. A malicious user can add newlines to their input (usually in encoded form) and "inject" those newlines into the returned HTTP response. This capability allows users to work around security headers and HTTP/1.1 framing headers by injecting entirely false responses or other new headers. The injected false responses may also be treated as the response to subsequent requests, which can lead to XSS, cache poisoning, and a number of other flaws. This issue was resolved by adding validation to the HTTPHeaders type, ensuring that there's no whitespace incorrectly present in the HTTP headers provided by users. As the existing API surface is non-failable, all invalid characters are replaced by linear whitespace.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.54%

41.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apple	Swiftnio	< 2.29.1
Apple	Swiftnio	>= 2.30.0, < 2.39.1
Apple	Swiftnio	>= 2.40.0, < 2.42.0

References

https://github.com/apple/swift-nio/security/advisories/GHSA-7fj7-39wj-c64fThird Party Advisory
https://github.com/apple/swift-nio/security/advisories/GHSA-7fj7-39wj-c64fThird Party Advisory

Timeline

Published: Sep 28, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-3215?

NIOHTTP1 and projects using it for generating HTTP responses can be subject to a HTTP Response Injection attack. This occurs when a HTTP/1.1 server accepts user generated input from an incoming request and reflects it into a HTTP/1.1 response header in some form. A malicious user can add newlines to their input (usually in encoded form) and "inject" those newlines into the returned HTTP response. This capability allows users to work around security headers and HTTP/1.1 framing headers by injecting entirely false responses or other new headers. The injected false responses may also be treated as the response to subsequent requests, which can lead to XSS, cache poisoning, and a number of other flaws. This issue was resolved by adding validation to the HTTPHeaders type, ensuring that there's no whitespace incorrectly present in the HTTP headers provided by users. As the existing API surface is non-failable, all invalid characters are replaced by linear whitespace.

How severe is CVE-2022-3215?

CVE-2022-3215 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.54% probability of exploitation in the next 30 days.

How do I fix CVE-2022-3215?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.