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Lorenzo Leonardini @pianka.it · 28/02/2025

Took me a while, but here is the full article! If you want to see some weird URL parsing behavior, here you can find a lot of them :) sec.leonardini.dev/blog/playing... Disclaimer: no exploits nor vulnerabilities in this post, just some broken code

sec.leonardini.dev

Playing with Bun's URL parser

During the latest SECCON CTF quals, I had the pleasure of reading the custom implementation of Bun's URL parser, and I found some... weird behaviors... Join me in this wonderful journey.

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Lorenzo Leonardini @pianka.it · 02/01/2025

Currenly playing around with Bun's URL parser, and I must say it's pretty fun. It's not vulnerable as it's never used raw, but expect a few GH issues and a blog post about it. Spoiling the least interesting quirk to keep you on your toes :) Hopefully I'm not ruining anybody's future challenge :')

The URL `http://a@b@c` is parsed to as username `a`, password `b` and hostname `c`

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Lorenzo Leonardini @pianka.it · 28/12/2024

TIL that in Go this snippet produces `/foo/bar`, and... I feel like that's.. wrong..? The HTTP server router does not handle this as `/foo/bar`, and parsing this with Node returns `/foo%2fbar` (which is what I expected) Does anyone have any insight on this?

u, _ := url.Parse("http://localhost/foo%2fbar")
fmt.Println(u.Path)

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Lorenzo Leonardini @pianka.it · 22/11/2024

Yesterday my first PHP CVE was published: CVE-2024-11234. In some specific configurations, this vulnerability could allow for CRLF injection when using stream contexts. sec.leonardini.dev/blog/cve-202... Many thanks to @minimalblue.bsky.social for reviewing my original report

sec.leonardini.dev

CVE-2024-11234: Configuring a proxy in a PHP stream context might allow for CRLF injection in URIs 🐘

A vulnerability in PHP might allow an attacker to perform SSRF attacks when unsanitized user-controlled data is used in stream functions if a proxy is used.

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Reposted by Lorenzo Leonardini

Marco Squarcina @minimalblue.bsky.social · 21/11/2024

Sharing CVE-2024-11234 affecting PHP. This vulnerability could lead to CRLF injection when using Stream Contexts under certain conditions. Discovered and reported by @p1anka.bsky.social, I only reviewed the report some time ago! github.com/php/php-src/...

github.com

Configuring a proxy in a stream context might allow for CRLF injection in URIs

### Summary Configuring a proxy in a [stream context](https://www.php.net/manual/en/stream.contexts.php) might allow for CRLF injection in URIs, resulting in HTTP request smuggling attacks. #...

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