{"id":"CVE-2020-12638","aliases":["EUVD-2020-4939","GHSA-jf2p-5456-5593"],"status":"published","title":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2,...","description":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2, ESP8266_NONOS_SDK devices through 3.0.3, and ESP8266_RTOS_SDK devices through 3.3. Broadcasting forged beacon frames forces a device to change its authentication mode to OPEN, effectively disabling its 802.11 encryption.","severity":{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.0045,"percentile":0.39397,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287","CWE-319"],"published":"2020-07-23T15:41:58Z","modified":"2026-10-20T10:51:47Z","products":[{"vendor":"espressif","product":"esp-idf"},{"vendor":"espressif","product":"esp8266_nonos_sdk"},{"vendor":"espressif","product":"esp8266_rtos_sdk"}],"references":[{"url":"https://github.com/espressif/esp-idf","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory"]},{"url":"https://github.com/espressif/ESP8266_NONOS_SDK","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory"]},{"url":"https://github.com/espressif/ESP8266_RTOS_SDK","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory"]},{"url":"https://lbsfilm.at/blog/wpa2-authenticationmode-downgrade-in-espressif-microprocessors","tags":["x_refsource_MISC","x_transferred","Exploit","Patch","Third Party Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-12638"},{"url":"https://github.com/advisories/GHSA-jf2p-5456-5593"}],"sources":{"cve":[{"id":"CVE-2020-12638","description":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2, ESP8266_NONOS_SDK devices through 3.0.3, and ESP8266_RTOS_SDK devices through 3.3. Broadcasting forged beacon frames forces a device to change its authentication mode to OPEN, effectively disabling its 802.11 encryption.","status":"published","published":"2020-07-23T15:41:58Z","modified":"2024-08-04T12:04:22.314Z","updated_at":"2026-11-02T14:35:52.925152Z"}],"euvd":[{"id":"EUVD-2020-4939","description":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2, ESP8266_NONOS_SDK devices through 3.0.3, and ESP8266_RTOS_SDK devices through 3.3. Broadcasting forged beacon frames forces a device to change its authentication mode to OPEN, effectively disabling its 802.11 encryption.","status":"published","published":"2020-07-23T15:41:58Z","modified":"2024-08-04T12:04:22Z","updated_at":"2026-11-03T03:07:39.896975Z"}],"ghsa":[{"id":"GHSA-jf2p-5456-5593","title":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2,...","description":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2, ESP8266_NONOS_SDK devices through 3.0.3, and ESP8266_RTOS_SDK devices through 3.3. Broadcasting forged beacon frames forces a device to change its authentication mode to OPEN, effectively disabling its 802.11 encryption.","status":"published","published":"2022-05-24T17:24:13Z","modified":"2023-01-29T05:03:57Z","cwes":["CWE-287"],"updated_at":"2026-11-02T14:45:26.08688Z"}],"nvd":[{"id":"CVE-2020-12638","description":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2, ESP8266_NONOS_SDK devices through 3.0.3, and ESP8266_RTOS_SDK devices through 3.3. Broadcasting forged beacon frames forces a device to change its authentication mode to OPEN, effectively disabling its 802.11 encryption.","status":"published","published":"2020-07-23T16:15:12.49Z","modified":"2026-06-17T02:52:02.963Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:A/AC:M/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-287","CWE-319"],"updated_at":"2026-11-02T14:06:10.086163Z"}],"osv":[{"id":"CVE-2020-12638","description":"An encryption-bypass issue was discovered on Espressif ESP-IDF devices through 4.2, ESP8266_NONOS_SDK devices through 3.0.3, and ESP8266_RTOS_SDK devices through 3.3. Broadcasting forged beacon frames forces a device to change its authentication mode to OPEN, effectively disabling its 802.11 encryption.","status":"published","published":"2020-07-23T16:15:12.49Z","modified":"2026-10-20T10:51:47.064317959Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:14.034736Z"}]}}