The Social Connect plugin for WordPress is vulnerable to authentication bypass in versions up to, and including, 1.2. This is due to insufficient verification on the OpenID server being supplied during the social login through the plugin. This makes it possible for unauthenticated attackers to log in as any existing user on the site, such as an administrator, if they have access to the email.

oidcc is the OpenID Connect client library for Erlang. Denial of Service (DoS) by Atom exhaustion is possible by calling `oidcc_provider_configuration_worker:get_provider_configuration/1` or `oidcc_provider_configuration_worker:get_jwks/1`. This issue has been patched in version(s)`3.1.2` & `3.2.0-beta.3`.

Mastodon is a free, open-source social network server based on ActivityPub. Mastodon allows new identities from configured authentication providers (CAS, SAML, OIDC) to attach to existing local users with the same e-mail address. This results in a possible account takeover if the authentication provider allows changing the e-mail address or multiple authentication providers are configured. When a user logs in through an external authentication provider for the first time, Mastodon checks the e-mail address passed by the provider to find an existing account. However, using the e-mail address alone means that if the authentication provider allows changing the e-mail address of an account, the Mastodon account can immediately be hijacked. All users logging in through external authentication providers are affected. The severity is medium, as it also requires the external authentication provider to misbehave. However, some well-known OIDC providers (like Microsoft Azure) make it very easy to accidentally allow unverified e-mail changes. Moreover, OpenID Connect also allows dynamic client registration. This issue has been addressed in versions 4.2.6, 4.1.14, 4.0.14, and 3.5.18. Users are advised to upgrade. There are no known workarounds for this vulnerability.

mod_auth_openidc is an OpenID Certified™ authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality. In affected versions missing input validation on mod_auth_openidc_session_chunks cookie value makes the server vulnerable to a denial of service (DoS) attack. An internal security audit has been conducted and the reviewers found that if they manipulated the value of the mod_auth_openidc_session_chunks cookie to a very large integer, like 99999999, the server struggles with the request for a long time and finally gets back with a 500 error. Making a few requests of this kind caused our server to become unresponsive. Attackers can craft requests that would make the server work very hard (and possibly become unresponsive) and/or crash with minimal effort. This issue has been addressed in version 2.4.15.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Dex is an identity service that uses OpenID Connect to drive authentication for other apps. Dex 2.37.0 serves HTTPS with insecure TLS 1.0 and TLS 1.1. `cmd/dex/serve.go` line 425 seemingly sets TLS 1.2 as minimum version, but the whole `tlsConfig` is ignored after `TLS cert reloader` was introduced in v2.37.0. Configured cipher suites are not respected either. This issue is fixed in Dex 2.38.0.

Authentik is an open-source Identity Provider. Authentik is a vulnerable to a reflected Cross-Site Scripting vulnerability via JavaScript-URIs in OpenID Connect flows with `response_mode=form_post`. This relatively user could use the described attacks to perform a privilege escalation. This vulnerability has been patched in versions 2023.10.6 and 2023.8.6.

Hail is an open-source, general-purpose, Python-based data analysis tool with additional data types and methods for working with genomic data. Hail relies on OpenID Connect (OIDC) email addresses from ID tokens to verify the validity of a user's domain, but because users have the ability to change their email address, they could create accounts and use resources in clusters that they should not have access to. For example, a user could create a Microsoft or Google account and then change their email to `test@example.org`. This account can then be used to create a Hail Batch account in Hail Batch clusters whose organization domain is `example.org`. The attacker is not able to access private data or impersonate another user, but they would have the ability to run jobs if Hail Batch billing projects are enabled and create Azure Tenants if they have Azure Active Directory Administrator access.

yii2-authclient is an extension that adds OpenID, OAuth, OAuth2 and OpenId Connect consumers for the Yii framework 2.0. In yii2-authclient prior to version 2.2.15, the Oauth2 PKCE implementation is vulnerable in 2 ways. First, the `authCodeVerifier` should be removed after usage (similar to `authState`). Second, there is a risk for a `downgrade attack` if PKCE is being relied on for CSRF protection. Version 2.2.15 contains a patch for the issue. No known workarounds are available.

yii2-authclient is an extension that adds OpenID, OAuth, OAuth2 and OpenId Connect consumers for the Yii framework 2.0. In yii2-authclient prior to version 2.2.15, the Oauth1/2 `state` and OpenID Connect `nonce` is vulnerable for a `timing attack` since it is compared via regular string comparison (instead of `Yii::$app->getSecurity()->compareString()`). Version 2.2.15 contains a patch for the issue. No known workarounds are available.

Jenkins OpenId Connect Authentication Plugin 2.6 and earlier improperly determines that a redirect URL after login is legitimately pointing to Jenkins, allowing attackers to perform phishing attacks.

Jenkins OpenId Connect Authentication Plugin 2.6 and earlier stores a password of a local user account used as an anti-lockout feature in a recoverable format, allowing attackers with access to the Jenkins controller file system to recover the plain text password of that account, likely gaining administrator access to Jenkins.

A Server-Side Request Forgery issue in the OpenID Connect Issuer in LemonLDAP::NG before 2.17.1 allows authenticated remote attackers to send GET requests to arbitrary URLs through the request_uri authorization parameter. This is similar to CVE-2020-10770.

A flaw was found in Keycloaks OpenID Connect user authentication, which may incorrectly authenticate requests. An authenticated attacker who could obtain information from a user request within the same realm could use that data to impersonate the victim and generate new session tokens. This issue could impact confidentiality, integrity, and availability.

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. In affected versions it may be possible for a deactivated user to login when using uncommon configurations. This only applies if any of the following are true: 1. JSON Web Tokens are enabled for login via the `jwt_config.enabled` configuration setting. 2. The local password database is enabled via the `password_config.enabled` and `password_config.localdb_enabled` configuration settings *and* a user's password is updated via an admin API after a user is deactivated. Note that the local password database is enabled by default, but it is uncommon to set a user's password after they've been deactivated. Installations that are configured to only allow login via Single Sign-On (SSO) via CAS, SAML or OpenID Connect (OIDC); or via an external password provider (e.g. LDAP) are not affected. If not using JSON Web Tokens, ensure that deactivated users do not have a password set. This issue has been addressed in version 1.85.0. Users are advised to upgrade.

user_oidc app is an OpenID Connect user backend for Nextcloud. Authentication can be broken/bypassed in user_oidc app. It is recommended that the Nextcloud user_oidc app is upgraded to 1.3.2

An issue has been discovered in GitLab EE affecting all versions starting from 15.10 before 15.10.5, all versions starting from 15.11 before 15.11.1. Under certain conditions when OpenID Connect is enabled on an instance, it may allow users who are marked as 'external' to become 'regular' users thus leading to privilege escalation for those users.

mod_auth_openidc is an authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality. In versions 2.0.0 through 2.4.13.1, when `OIDCStripCookies` is set and a crafted cookie supplied, a NULL pointer dereference would occur, resulting in a segmentation fault. This could be used in a Denial-of-Service attack and thus presents an availability risk. Version 2.4.13.2 contains a patch for this issue. As a workaround, avoid using `OIDCStripCookies`.

Cleartext Transmission of Sensitive Information vulnerability in ForgeRock Inc. OpenIDM and Java Remote Connector Server (RCS) LDAP Connector on Windows, MacOS, Linux allows Remote Services with Stolen Credentials.This issue affects OpenIDM and Java Remote Connector Server (RCS): from 1.5.20.9 through 1.5.20.13.

Jenkins OpenId Connect Authentication Plugin 2.4 and earlier does not invalidate the previous session on login.

OpenSearch is an open source distributed and RESTful search engine. OpenSearch uses JWTs to store role claims obtained from the Identity Provider (IdP) when the authentication backend is SAML or OpenID Connect. There is an issue in how those claims are processed from the JWTs where the leading and trailing whitespace is trimmed, allowing users to potentially claim roles they are not assigned to if any role matches the whitespace-stripped version of the roles they are a member of. This issue is only present for authenticated users, and it requires either the existence of roles that match, not considering leading/trailing whitespace, or the ability for users to create said matching roles. In addition, the Identity Provider must allow leading and trailing spaces in role names. OpenSearch 1.0.0-1.3.7 and 2.0.0-2.4.1 are affected. Users are advised to upgrade to OpenSearch 1.3.8 or 2.5.0. There are no known workarounds for this issue.