<Issue Description> Spring Security OAuth versions 2.5.x prior to 2.5.2 and older unsupported versions are susceptible to a Denial-of-Service (DoS) attack via the initiation of the Authorization Request in an OAuth 2.0 Client application. A malicious user or attacker can send multiple requests initiating the Authorization Request for the Authorization Code Grant, which has the potential of exhausting system resources using a single session. This vulnerability exposes OAuth 2.0 Client applications only.

Spring Security versions 5.2.x prior to 5.2.4 and 5.3.x prior to 5.3.2 contain a signature wrapping vulnerability during SAML response validation. When using the spring-security-saml2-service-provider component, a malicious user can carefully modify an otherwise valid SAML response and append an arbitrary assertion that Spring Security will accept as valid.

Spring Security OAuth could allow a remote attacker to conduct phishing attacks, caused by an open redirect vulnerability in authorization endpoint. An attacker could exploit this vulnerability using a specially-crafted URL to redirect a victim to arbitrary Web sites.

Spring Security OAuth, versions 2.3 prior to 2.3.4, and 2.2 prior to 2.2.3, and 2.1 prior to 2.1.3, and 2.0 prior to 2.0.16, and older unsupported versions could be susceptible to a privilege escalation under certain conditions. A malicious user or attacker can craft a request to the approval endpoint that can modify the previously saved authorization request and lead to a privilege escalation on the subsequent approval. This scenario can happen if the application is configured to use a custom approval endpoint that declares AuthorizationRequest as a controller method argument.

External References:

https://pivotal.io/security/cve-2018-15758

A flaw was found in Spring Security OAuth, versions 2.3 prior to 2.3.3, 2.2 prior to 2.2.2, 2.1 prior to 2.1.2, 2.0 prior to 2.0.15 and older unsupported versions contains a remote code execution vulnerability. A malicious user or attacker can craft an authorization request to the authorization endpoint that can lead to remote code execution when the resource owner is forwarded to the approval endpoint.

References: https://pivotal.io/security/cve-2018-1260

A flaw was found in Spring Security in combination with Spring Framework versions prior to 5.0.6 contains an authorization bypass when using method security. An unauthorized malicious user can gain unauthorized access to methods that should be restricted.

References: https://pivotal.io/security/cve-2018-1258

When processing authorization requests using the whitelabel views in Spring Security OAuth 2.0.0 to 2.0.9 and 1.0.0 to 1.0.5, the responsetype parameter value was executed as Spring SpEL which enabled a malicious user to trigger remote code execution via the crafting of the value for responsetype.