CVE-2026-100854

AzuraCast before 0.23.6 lacks RequireInternalConnection middleware on the Liquidsoap API endpoint and incorrectly derives the AutoDJ flag from header presence rather than validated value. Users with View station permission can inject arbitrary now-playing metadata, disrupt live broadcasts, and disclose filesystem paths.

AzuraCast before 0.23.6 lacks RequireInternalConnection middleware on the Liquidsoap API endpoint and incorrectly derives the AutoDJ flag from header presence rather than validated value. Users with View station permission can inject arbitrary now-playing metadata, disrupt live broadcasts, and disclose filesystem paths.

Summary

The /api/internal/{station_id}/liquidsoap/{action} endpoint is accessible from the public web interface because it lacks the RequireInternalConnection middleware that protects other internal endpoints (/sftp-auth, /sftp-event). Combined with a logic flaw where the $asAutoDj flag is set based on the presence of the X-Liquidsoap-Api-Key header rather than its validated value, any user with the basic View station permission can invoke privileged Liquidsoap commands — injecting arbitrary now-playing metadata visible to all listeners, disrupting live broadcast tracking, and disclosing absolute filesystem paths.

Details

Issue 1: Missing RequireInternalConnection middleware

In backend/config/routes/api_internal.php, the liquidsoap route group (lines 17-21) lacks the RequireInternalConnection middleware:

// Lines 17-21 — NO RequireInternalConnection
$group->map(
    ['GET', 'POST'],
    '/liquidsoap/{action}',
    Controller\Api\Internal\LiquidsoapAction::class
)->setName('api:internal:liquidsoap');

Compare with sftp endpoints that correctly apply it:

// Lines 32-34 — HAS RequireInternalConnection
$group->post('/sftp-auth', Controller\Api\Internal\SftpAuthAction::class)
    ->setName('api:internal:sftp-auth')
    ->add(Middleware\RequireInternalConnection::class);

The nginx config (util/docker/web/nginx/azuracast.conf.tmpl) only sets the IS_INTERNAL FastCGI parameter on the internal port 6010 listener (line 44), not on the public-facing server block (ports 80/443). Without the middleware, the endpoint is fully accessible from the public internet.

Issue 2: $asAutoDj derived from header presence, not validated value

In backend/src/Controller/Api/Internal/LiquidsoapAction.php:

// Line 34 — checks header PRESENCE, not value
$asAutoDj = $request->hasHeader('X-Liquidsoap-Api-Key');

// Lines 38-44 — key value only checked when ACL FAILS
$acl = $request->getAcl();
if (!$acl->isAllowed(StationPermissions::View, $station->id)) {
    $authKey = $request->getHeaderLine('X-Liquidsoap-Api-Key');
    if (!$station->validateAdapterApiKey($authKey)) {
        throw new RuntimeException('Invalid API key.');
    }
}

When a user authenticates via session/API key and has StationPermissions::View, the ACL check passes and the adapter API key is never validated. But $asAutoDj is already true from line 34 because the header is present (with any arbitrary value).

Affected commands:

• FeedbackCommand (backend/src/Radio/Backend/Liquidsoap/Command/FeedbackCommand.php:36): Guard if (!$asAutoDj) return false; bypassed — creates SongHistory records and forces NowPlaying cache updates
• DjOffCommand (backend/src/Radio/Backend/Liquidsoap/Command/DjOffCommand.php:24): Guard bypassed — calls $this->streamerRepo->onDisconnect($station) which ends all active broadcasts and sets $station->is_streamer_live = false
• DjOnCommand (backend/src/Radio/Backend/Liquidsoap/Command/DjOnCommand.php:31): Guard bypassed — calls $this->streamerRepo->onConnect($station, $user) with attacker-controlled username
• CopyCommand (backend/src/Radio/Backend/Liquidsoap/Command/CopyCommand.php:18): No $asAutoDj guard at all — returns absolute filesystem paths via $mediaFs->getLocalPath($uri)

PoC

Prerequisites: A user account with StationPermissions::View on station ID 1 (the lowest station-level permission). Obtain a session cookie or API key for this user.

1. Inject arbitrary now-playing metadata (FeedbackCommand):

curl -X POST 'https://target/api/internal/1/liquidsoap/feedback' \
  -H 'X-API-Key: <view-user-api-key>' \
  -H 'X-Liquidsoap-Api-Key: anything' \
  -H 'Content-Type: application/json' \
  -d '{"artist": "INJECTED", "title": "Fake Song Title"}'

Expected: Should reject — user does not have the adapter API key. Actual: Returns true. The injected artist/title appears in /api/nowplaying/1 for all…

AzuraCast before 0.23.6 lacks RequireInternalConnection middleware on the Liquidsoap API endpoint and incorrectly derives the AutoDJ flag from header presence rather than validated value. Users with View station permission can inject arbitrary now-playing metadata, disrupt live broadcasts, and disclose filesystem paths.

AzuraCast before 0.23.6 lacks RequireInternalConnection middleware on the Liquidsoap API endpoint and incorrectly derives the AutoDJ flag from header presence rather than validated value. Users with View station permission can inject arbitrary now-playing metadata, disrupt live broadcasts, and disclose filesystem paths.

AzuraCast before 0.23.6 lacks RequireInternalConnection middleware on the Liquidsoap API endpoint and incorrectly derives the AutoDJ flag from header presence rather than validated value. Users with View station permission can inject arbitrary now-playing metadata, disrupt live broadcasts, and disclose filesystem paths.

Summary

The /api/internal/{station_id}/liquidsoap/{action} endpoint is accessible from the public web interface because it lacks the RequireInternalConnection middleware that protects other internal endpoints (/sftp-auth, /sftp-event). Combined with a logic flaw where the $asAutoDj flag is set based on the presence of the X-Liquidsoap-Api-Key header rather than its validated value, any user with the basic View station permission can invoke privileged Liquidsoap commands — injecting arbitrary now-playing metadata visible to all listeners, disrupting live broadcast tracking, and disclosing absolute filesystem paths.

Details

Issue 1: Missing RequireInternalConnection middleware

In backend/config/routes/api_internal.php, the liquidsoap route group (lines 17-21) lacks the RequireInternalConnection middleware:

// Lines 17-21 — NO RequireInternalConnection
$group->map(
    ['GET', 'POST'],
    '/liquidsoap/{action}',
    Controller\Api\Internal\LiquidsoapAction::class
)->setName('api:internal:liquidsoap');

Compare with sftp endpoints that correctly apply it:

// Lines 32-34 — HAS RequireInternalConnection
$group->post('/sftp-auth', Controller\Api\Internal\SftpAuthAction::class)
    ->setName('api:internal:sftp-auth')
    ->add(Middleware\RequireInternalConnection::class);

The nginx config (util/docker/web/nginx/azuracast.conf.tmpl) only sets the IS_INTERNAL FastCGI parameter on the internal port 6010 listener (line 44), not on the public-facing server block (ports 80/443). Without the middleware, the endpoint is fully accessible from the public internet.

Issue 2: $asAutoDj derived from header presence, not validated value

In backend/src/Controller/Api/Internal/LiquidsoapAction.php:

// Line 34 — checks header PRESENCE, not value
$asAutoDj = $request->hasHeader('X-Liquidsoap-Api-Key');

// Lines 38-44 — key value only checked when ACL FAILS
$acl = $request->getAcl();
if (!$acl->isAllowed(StationPermissions::View, $station->id)) {
    $authKey = $request->getHeaderLine('X-Liquidsoap-Api-Key');
    if (!$station->validateAdapterApiKey($authKey)) {
        throw new RuntimeException('Invalid API key.');
    }
}

When a user authenticates via session/API key and has StationPermissions::View, the ACL check passes and the adapter API key is never validated. But $asAutoDj is already true from line 34 because the header is present (with any arbitrary value).

Affected commands:

• FeedbackCommand (backend/src/Radio/Backend/Liquidsoap/Command/FeedbackCommand.php:36): Guard if (!$asAutoDj) return false; bypassed — creates SongHistory records and forces NowPlaying cache updates
• DjOffCommand (backend/src/Radio/Backend/Liquidsoap/Command/DjOffCommand.php:24): Guard bypassed — calls $this->streamerRepo->onDisconnect($station) which ends all active broadcasts and sets $station->is_streamer_live = false
• DjOnCommand (backend/src/Radio/Backend/Liquidsoap/Command/DjOnCommand.php:31): Guard bypassed — calls $this->streamerRepo->onConnect($station, $user) with attacker-controlled username
• CopyCommand (backend/src/Radio/Backend/Liquidsoap/Command/CopyCommand.php:18): No $asAutoDj guard at all — returns absolute filesystem paths via $mediaFs->getLocalPath($uri)

PoC

Prerequisites: A user account with StationPermissions::View on station ID 1 (the lowest station-level permission). Obtain a session cookie or API key for this user.

1. Inject arbitrary now-playing metadata (FeedbackCommand):

curl -X POST 'https://target/api/internal/1/liquidsoap/feedback' \
  -H 'X-API-Key: <view-user-api-key>' \
  -H 'X-Liquidsoap-Api-Key: anything' \
  -H 'Content-Type: application/json' \
  -d '{"artist": "INJECTED", "title": "Fake Song Title"}'

Expected: Should reject — user does not have the adapter API key. Actual: Returns true. The injected artist/title appears in /api/nowplaying/1 for all…