CVE-2018-20840

An unhandled exception vulnerability exists during Google Sign-In with Google API C++ Client before 2019-04-10. It potentially causes an outage of third-party services that were not designed to recover from exceptions. On the client, ID token handling can cause an unhandled exception because of misinterpretation of an integer as a string, resulting in denial-of-service and then other users can no longer login/sign-in to the affected third-party service. Once this third-party service uses Google Sign-In with google-api-cpp-client, a malicious user can trigger this client/auth/oauth2_authorization.cc vulnerability by requesting the client to receive the ID token from a Google authentication server.

• CWE-754

• https://github.com/google/google-api-cpp-client/issues/57Exploit, Issue Tracking, Third Party Advisory
• https://github.com/google/google-api-cpp-client/pull/58Issue Tracking, Patch, Third Party Advisory
• https://github.com/google/google-api-cpp-client/issues/57Exploit, Issue Tracking, Third Party Advisory
• https://github.com/google/google-api-cpp-client/pull/58Issue Tracking, Patch, Third Party Advisory

Published

May 30, 2019

Last Modified

Jun 17, 2026

Status

Modified

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