Unix `BROWSER` handling allows browser argument injection
Collected exploitation and prediction evidence
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osv · RUSTSEC-2026-0257
PublishedOn Unix platforms handled by `src/unix.rs`, affected versions substitute the caller-supplied URL into the `BROWSER` environment-variable template before tokenizing the resulting string with `split_ascii_whitespace()`. If an application passes an attacker-controlled non-HTTP(S) URL whose parsed form retains spaces and the effective `BROWSER` template contains `%s`, text that should remain within one URL argument becomes additional browser arguments. The issue was reproduced with Chromium by injecting `--remote-debugging-port`, which exposed a local DevTools endpoint, and `--proxy-server`, which redirected browser traffic through an attacker-controlled proxy. The available arguments and resulting impact depend on the browser launched by the affected application. Version 1.2.2 fixes the issue by tokenizing the `BROWSER` template before substituting the URL, preserving the URL as part of a single argument. Users should upgrade to version 1.2.2 or later. Applications that only need HTTP(S) URLs can also enable the crate's `hardened` feature as defense in depth. This issue was reported by [@dywzju09-blip](https://github.com/dywzju09-blip).
- Source published
- 29 Jul 2026 12:00:00 UTC
- Source modified
- 12 Oct 2026 18:00:10 UTC
- Observed here
- 24 Oct 2026 13:19:54 UTC
- Source terms
- OSV · upstream source license applies
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