CVE-2023-0040 Async HTTP Client has CRLF Injection vulnerability in HTTP request headers

What is CVE-2023-0040?

CVE-2023-0040 is a high-severity vulnerability in Swift Project Async HTTP Client, published on 18 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Versions of Async HTTP Client prior to 1.13.2 are vulnerable to a form of targeted request manipulation called CRLF injection. This vulnerability was the result of insufficient validation of HTTP header field values before sending them to the network. Users are vulnerable if they pass untrusted data into HTTP header field values without prior sanitisation. Common use-cases here might be to place usernames from a database into HTTP header fields. This vulnerability allows attackers to inject new HTTP header fields, or entirely new requests, into the data stream. This can cause requests to be understood very differently by the remote server than was intended. In general, this is unlikely to result in data disclosure, but it can result in a number of logical errors and other misbehaviours.

Weakness: CWE-74, CWE-93

Which versions are affected by CVE-2023-0040?

8 open source packages ship an affected version, including github.com/swift-server/async-http-client. It affects 1 product.

Products include Asynchttpclient Project Async-Http-Client.

How do I fix CVE-2023-0040?

Upgrade github.com/swift-server/async-http-client to a fixed version for your release line: 1.4.1, 1.12.1, 1.13.2 or 1.9.1.

Is CVE-2023-0040 being exploited?

There is no known exploitation of CVE-2023-0040 in the wild and no public exploit code.

Other vulnerabilities in Swift Project Async HTTP Client

• CVE-2017-14063 Improper Input Validation in async-http-client High 7.5
• CVE-2026-45300 async-http-client: Cookie header not stripped on cross-origin redirect High 7.4

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-v3r5-pjpm-mwgq.