{"id":"CVE-2023-50714","aliases":["EUVD-2023-3295","GHSA-rw54-6826-c8j5"],"status":"published","title":"The Oauth2 PKCE implementation is vulnerable","description":"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.","severity":{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00492,"percentile":0.42715,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-287","CWE-347","CWE-918"],"published":"2023-12-18T19:34:20Z","modified":"2026-10-28T02:30:58Z","fixes":[{"ecosystem":"Packagist","package":"yiisoft/yii2-authclient","fixed_in":["2.2.15"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"yiisoft/yii2-authclient","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.2.15"}]}]},{"source":"osv","ecosystem":"Packagist","package":"yiisoft/yii2-authclient","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.2.15"}]}],"versions":["2.0.0","2.0.0-beta","2.0.0-rc","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.1.0","2.1.1","2.1.2","2.1.3","2.1.4","2.1.5","2.1.6","2.1.7","2.1.8","2.2.0","2.2.1","2.2.10","2.2.11","2.2.12","2.2.13","2.2.14","2.2.2","2.2.3","2.2.4","2.2.5","2.2.6","2.2.7","2.2.8","2.2.9"]}],"products":[{"vendor":"yiiframework","product":"yii2-authclient"},{"vendor":"yiisoft","product":"yii2-authclient"}],"references":[{"url":"https://github.com/yiisoft/yii2-authclient/security/advisories/GHSA-rw54-6826-c8j5","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Third Party Advisory","advisory","web"]},{"url":"https://github.com/yiisoft/yii2-authclient/commit/721ed974bc44137437b0cdc8454e137fff8db213","tags":["x_refsource_MISC","x_transferred","Patch","fix","web"]},{"url":"https://github.com/yiisoft/yii2-authclient/blob/0d1c3880f4d79e20aa1d77c012650b54e69695ff/src/OAuth1.php#L158","tags":["x_refsource_MISC","x_transferred","Product","web"]},{"url":"https://github.com/yiisoft/yii2-authclient/blob/0d1c3880f4d79e20aa1d77c012650b54e69695ff/src/OAuth2.php#L121","tags":["x_refsource_MISC","x_transferred","Product","web"]},{"url":"https://github.com/yiisoft/yii2-authclient/blob/0d1c3880f4d79e20aa1d77c012650b54e69695ff/src/OpenIdConnect.php#L420","tags":["x_refsource_MISC","x_transferred","Product","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-50714","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-rw54-6826-c8j5"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/50xxx/CVE-2023-50714.json","tags":["advisory"]},{"url":"https://github.com/yiisoft/yii2-authclient","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2023-50714","title":"The Oauth2 PKCE implementation is vulnerable","description":"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.","status":"published","published":"2023-12-22T18:30:03.118Z","modified":"2024-11-27T15:43:11.763Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-918","CWE-347"],"updated_at":"2026-11-02T14:35:34.55015Z"}],"euvd":[{"id":"EUVD-2023-3295","description":"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.","status":"published","published":"2023-12-22T18:30:03Z","modified":"2024-11-27T15:43:11Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium"}],"updated_at":"2026-11-03T00:04:45.657538Z"}],"ghsa":[{"id":"GHSA-rw54-6826-c8j5","title":"yiisoft/yii2-authclient's Oauth2 PKCE implementation is vulnerable","description":"### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nOriginal Report:\n\n\u003e The Oauth2 PKCE implementation is vulnerable in 2 ways:\n\u003e 1. The `authCodeVerifier` should be removed after usage (similar to 'authState')\n\u003e 2. There is a risk for a \"downgrade attack\" if PKCE is being relied on for CSRF protection.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\n2.2.15\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nnot known yet.\n\n### References\n_Are there any links users can visit to find out more?_\n","status":"published","published":"2023-12-18T19:34:20Z","modified":"2023-12-22T22:24:11Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium"}],"cwes":["CWE-287","CWE-347"],"updated_at":"2026-11-02T14:37:28.04129Z"}],"nvd":[{"id":"CVE-2023-50714","description":"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.","status":"published","published":"2023-12-22T19:15:09.057Z","modified":"2026-06-17T06:39:50.32Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-347","CWE-918","CWE-287"],"updated_at":"2026-11-02T14:08:57.117371Z"}],"osv":[{"id":"CVE-2023-50714","title":"The Oauth2 PKCE implementation is vulnerable","description":"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.","status":"published","published":"2023-12-22T18:30:03.118Z","modified":"2026-10-28T02:30:58.032348029Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium"}],"cwes":["CWE-347","CWE-918"],"updated_at":"2026-11-02T15:44:35.245372Z"},{"id":"GHSA-rw54-6826-c8j5","title":"yiisoft/yii2-authclient's Oauth2 PKCE implementation is vulnerable","description":"### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nOriginal Report:\n\n\u003e The Oauth2 PKCE implementation is vulnerable in 2 ways:\n\u003e 1. The `authCodeVerifier` should be removed after usage (similar to 'authState')\n\u003e 2. There is a risk for a \"downgrade attack\" if PKCE is being relied on for CSRF protection.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\n2.2.15\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nnot known yet.\n\n### References\n_Are there any links users can visit to find out more?_\n","status":"published","published":"2023-12-18T19:34:20Z","modified":"2026-09-10T03:50:09.131571556Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"medium"}],"cwes":["CWE-287","CWE-347"],"updated_at":"2026-11-02T15:46:56.281047Z"}]}}