`minstrel admin reset-password` copied the new login password into
subsonic_password, which is stored in plain text because Subsonic t/s
sign-in needs it. Every account recovered through the CLI had its login
password readable in the database, and changing the password later left
the copy behind.

- reset-password now changes only password_hash.
- Migration 0064 clears every subsonic_password, removing the copies.
- Settings gets a Subsonic password card: the server generates a random
  password, shows it once, and it can be regenerated or turned off
  (GET/POST/DELETE /api/me/subsonic-password, audited). Generated rather
  than user-chosen so it can never be a reused password.
- docs/security.md describes the separate password instead of the known
  issue.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-06 10:54:30 -04:00

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Security notes

What Minstrel does to protect accounts, and the reasoning behind the decisions that look odd at first. For deployment steps, see hosting.

Accounts and sessions

Passwords are stored as bcrypt hashes.
Login, registration and password reset are rate-limited: 10 failed sign-ins per account and 50 per address per 15 minutes, with similar limits on register, forgot-password and reset. The Subsonic /rest API shares the login limits. An unknown username takes as long to reject as a wrong password, so timing doesn't reveal which accounts exist.
Sessions are random 256-bit tokens; the server stores only their SHA-256. A session ends after 30 days unused or 365 days in total. Changing your password signs out your other devices; a password reset, or an admin resetting it, signs out all of them.
API keys (the OpenSubsonic apiKey) are stored as SHA-256 too, so a key is shown once, when you generate it in Settings, and can only be replaced after that.
The first account on an empty server needs the setup token from the server log (see hosting).
Password-reset links are built only from the configured public address, never from the request's Host header.

Requests

Request bodies are capped at 4 MiB and must arrive within 30 seconds. Streams and the live-event connection are unaffected.
Every response carries X-Content-Type-Options: nosniff, Referrer-Policy: strict-origin-when-cross-origin, a restrictive Permissions-Policy and X-Frame-Options: DENY. The web app also gets a Content-Security-Policy that allows only its own scripts, by hash.
Media responses are Cache-Control: private, so a shared cache never keeps one user's audio or artwork for another.

CSRF: SameSite cookies plus JSON-only writes

There are no CSRF tokens. The session cookie is SameSite=Strict, so browsers don't send it with requests that start on another site. That leaves one gap: SameSite treats every subdomain of the same registrable domain as the same site, so a different app on other.example.com could still send a request carrying the cookie. To close it, any state-changing /api request authenticated by the cookie must have a JSON body (Content-Type: application/json) or no body at all. An HTML form or a script on another origin can't send JSON without a CORS preflight, and Minstrel answers no cross-origin preflight. Requests authenticated with a bearer token or the Subsonic query parameters carry nothing a browser attaches on its own, so they aren't checked.

Classic Subsonic clients sign in with t and s: the MD5 of the password followed by a random salt. To check that, the server has to know the password itself, so supporting this sign-in method means storing a password Minstrel can read. That is the Subsonic password, and it is the only credential Minstrel keeps unhashed.

The recommended way in is the API key. Clients that support the OpenSubsonic apiKey should use it. The key is stored hashed and can be replaced at any time in Settings.
The Subsonic password is never your login password. Minstrel generates it (Settings → Subsonic password), shows it once, and lets you replace or turn it off. Because it is random, a copy of the database exposes access to this server's Subsonic API and nothing else: it can't be a password you also use somewhere else.
t/s and p= sign-in are off for an account until it has a Subsonic password. Plain p= sign-in is additionally off server-wide unless subsonic.allow_plaintext_password is enabled.
minstrel admin reset-password changes only the login password. Older versions also copied it into the Subsonic password; upgrading clears every Subsonic password once, so those copies are gone. An account that used t/s sign-in needs a new Subsonic password generated in Settings.

Android allows plain HTTP

The Android app permits cleartext connections, for two reasons that can't be narrowed to a list of hosts. The server address is whatever the user types, and many self-hosted servers run plain HTTP on a LAN. And UPnP, DLNA and Sonos speakers are controlled over plain HTTP at addresses that are only known once they're discovered. The reasoning lives in android/app/src/main/res/xml/network_security_config.xml.

This doesn't weaken app updates: an APK altered in transit fails the platform's signature check. It does mean a server reached over plain HTTP across the internet exposes the session cookie in transit, which is why the hosting guide puts public servers behind HTTPS.

On the phone, the session cookie is encrypted with a key held in the Android Keystore, so a copy of the app's files doesn't yield a usable session.

Build pipeline

Nothing is published unless every check passes: the Go, integration, web and Android test suites, govulncheck against the toolchain that builds the image, and npm audit on the packages that ship to the browser. See .gitea/workflows/release.yml.

Reporting a problem

Open an issue on the repository, or contact the maintainer privately first if it's something that shouldn't be public until fixed.

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