Headline
CVE-2023-38489: Invalidate session on password change · getkirby/kirby@7a0a201
Kirby is a content management system. A vulnerability in versions prior to 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, and 3.9.6 affects all Kirby sites with user accounts (unless Kirby’s API and Panel are disabled in the config). It can only be abused if a Kirby user is logged in on a device or browser that is shared with potentially untrusted users or if an attacker already maliciously used a previous password to log in to a Kirby site as the affected user.
Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization. In the variation described in this advisory, it allows attackers to stay logged in to a Kirby site on another device even if the logged in user has since changed their password. Kirby did not invalidate user sessions that were created with a password that was since changed by the user or by a site admin. If a user changed their password to lock out an attacker who was already in possession of the previous password or of a login session on another device or browser, the attacker would not be reliably prevented from accessing the Kirby site as the affected user.
The problem has been patched in Kirby 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, and Kirby 3.9.6. In all of the mentioned releases, the maintainers have updated the authentication implementation to keep track of the hashed password in each active session. If the password changed since the login, the session is invalidated. To enforce this fix even if the vulnerability was previously abused, all users are logged out from the Kirby site after updating to one of the patched releases.
Expand Up @@ -5,6 +5,7 @@ use Kirby\Exception\NotFoundException; use Kirby\Exception\PermissionException; use Kirby\Filesystem\Dir; use Kirby\Filesystem\F; use Kirby\Session\AutoSession; use Throwable;
Expand All @@ -15,13 +16,13 @@ class AuthTest extends TestCase { protected $app; protected $auth; protected $fixtures; protected $tmp;
public function setUp(): void { $this->app = new App([ ‘roots’ => [ ‘index’ => $this->fixtures = __DIR__ . ‘/fixtures/AuthTest’ ‘index’ => $this->tmp = __DIR__ . ‘/tmp’ ], ‘options’ => [ ‘api’ => [ Expand All @@ -41,19 +42,21 @@ public function setUp(): void [ ‘email’ => '[email protected]’, ‘id’ => 'homer’, ‘password’ => password_hash('springfield123’, PASSWORD_DEFAULT) ‘password’ => $hash = password_hash('springfield123’, PASSWORD_DEFAULT) ] ] ]); Dir::make($this->fixtures . ‘/site/accounts’); Dir::make($this->tmp . ‘/site/accounts/homer’); F::write($this->tmp . '/site/accounts/homer/.htpasswd’, $hash); touch($this->tmp . '/site/accounts/homer/.htpasswd’, 1337000000);
$this->auth = $this->app->auth(); }
public function tearDown(): void { $this->app->session()->destroy(); Dir::remove($this->fixtures); Dir::remove($this->tmp); App::destroy(); }
Expand Down Expand Up @@ -254,7 +257,7 @@ public function testTypeSession() * @covers ::status * @covers ::user */ public function testUserSession1() public function testUserSession() { $session = $this->app->session(); $session->set('kirby.userId’, ‘marge’); Expand Down Expand Up @@ -286,10 +289,11 @@ public function testUserSession1() * @covers ::status * @covers ::user */ public function testUserSession2() public function testUserSessionManualSession() { $session = (new AutoSession($this->app->root(‘sessions’)))->createManually(); $session->set('kirby.userId’, ‘homer’); $session->set('kirby.loginTimestamp’, 1337000000);
$user = $this->auth->user($session); $this->assertSame('[email protected]’, $user->email()); Expand All @@ -300,6 +304,47 @@ public function testUserSession2() ], $this->auth->status()->toArray()); }
/** * @covers ::status * @covers ::user */ public function testUserSessionOldTimestamp() { $session = $this->app->session(); $session->set('kirby.userId’, ‘homer’); $session->set('kirby.loginTimestamp’, 1000000000);
$this->assertNull($this->auth->user()); $this->assertSame([ ‘challenge’ => null, ‘email’ => null, ‘status’ => ‘inactive’ ], $this->auth->status()->toArray());
// user should be logged out completely $this->assertSame([], $session->data()->get()); }
/** * @covers ::status * @covers ::user */ public function testUserSessionNoTimestamp() { $session = $this->app->session(); $session->set('kirby.userId’, ‘homer’);
$this->assertNull($this->auth->user()); $this->assertSame([ ‘challenge’ => null, ‘email’ => null, ‘status’ => ‘inactive’ ], $this->auth->status()->toArray());
// user should be logged out completely $this->assertSame([], $session->data()->get()); }
/** * @covers ::status * @covers ::user Expand Down
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### TL;DR This vulnerability affects all Kirby sites with user accounts (unless Kirby's API and Panel are disabled in the config). It can only be abused if a Kirby user is logged in on a device or browser that is shared with potentially untrusted users or if an attacker already maliciously used a previous password to log in to a Kirby site as the affected user. ---- ### Introduction Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization. In the variation described in this advisory, it allows attackers to stay logged in to a Kirby site on another device or browser even if the logged in user has since changed their password. ### Impact Kirby did not invalidate old user sessions after the user password was changed by the user or by a site admin. If a user changed their password to lock out an attacker who was already in possession of the previous password or of a login session on another device or b...