Impact

What kind of vulnerability is it? Who is impacted?

Original Report:

The Oauth1/2 "state" and OpenID Connect "nonce" is vulnerable for a "timing attack" since it's compared via regular string
comparison (instead of Yii::$app->getSecurity()->compareString()).

Affected Code:

1. OAuth 1 "state"

   yii2-authclient/src/OAuth1.php

   Line 158 in 0d1c388

   if (strcmp($requestToken->getToken(), $oauthToken) !== 0) {

2. OAuth 2 "state"

   yii2-authclient/src/OAuth2.php

   Line 121 in 0d1c388

   if (!isset($incomingState) || empty($authState) || strcmp($incomingState, $authState) !== 0) {

3. OpenID Connect "nonce"

   yii2-authclient/src/OpenIdConnect.php

   Line 420 in 0d1c388

   if (!isset($jwsData['nonce']) || empty($authNonce) || strcmp($jwsData['nonce'], $authNonce) !== 0) {

Patches

Has the problem been patched? What versions should users upgrade to?

TBD: Replace strcmp with Yii::$app->getSecurity()->compareString()).

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

not as far as I see.

References

Are there any links users can visit to find out more?