{"id":"CVE-2018-20840","aliases":["EUVD-2018-13380","GHSA-jw9r-r4mj-mpxx"],"status":"published","title":"An unhandled exception vulnerability exists during Google Sign-In with Google API C++ Client...","description":"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.","severity":{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.00651,"percentile":0.51479,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-754"],"published":"2019-05-30T15:58:10Z","modified":"2026-06-17T01:53:34Z","products":[{"vendor":"google","product":"api_c\\+\\+_client"}],"references":[{"url":"https://github.com/google/google-api-cpp-client/pull/58","tags":["x_refsource_MISC","x_transferred","Issue Tracking","Patch","Third Party Advisory"]},{"url":"https://github.com/google/google-api-cpp-client/issues/57","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-20840"},{"url":"https://github.com/advisories/GHSA-jw9r-r4mj-mpxx"}],"sources":{"cve":[{"id":"CVE-2018-20840","description":"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.","status":"published","published":"2019-05-30T15:58:10Z","modified":"2024-08-05T12:12:28.562Z","updated_at":"2026-11-02T14:35:00.237825Z"}],"euvd":[{"id":"EUVD-2018-13380","description":"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.","status":"published","published":"2019-05-30T15:58:10Z","modified":"2024-08-05T12:12:28Z","updated_at":"2026-11-03T02:39:29.769885Z"}],"ghsa":[{"id":"GHSA-jw9r-r4mj-mpxx","title":"An unhandled exception vulnerability exists during Google Sign-In with Google API C++ Client...","description":"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.","status":"published","published":"2022-05-24T16:46:53Z","modified":"2024-04-04T00:49:55Z","cvss":[{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T14:55:52.724602Z"}],"nvd":[{"id":"CVE-2018-20840","description":"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.","status":"published","published":"2019-05-30T16:29:01.323Z","modified":"2026-06-17T01:53:34.4Z","cvss":[{"version":"3.0","score":8.6,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T14:04:57.307075Z"}]}}