{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:espressif:esp-idf:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "4.2"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "ee899cb2aac50349bb83524910f4f34920579386"
            }
          ],
          "repo": "https://github.com/espressif/esp-idf",
          "type": "GIT"
        }
      ]
    },
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:espressif:esp8266_nonos_sdk:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "3.0.3"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "3fe474e040450e0ab72ea75f8f00c3d9c6279025"
            }
          ],
          "repo": "https://github.com/espressif/esp8266_nonos_sdk",
          "type": "GIT"
        }
      ]
    },
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:espressif:esp8266_rtos_sdk:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "3.3"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "9f9ee5a97b4818b110bde88eb60c602569a0038d"
            }
          ],
          "repo": "https://github.com/espressif/esp8266_rtos_sdk",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {},
  "details": "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.",
  "id": "CVE-2020-12638",
  "modified": "2026-07-08T05:38:32.958036484Z",
  "published": "2020-07-23T16:15:12.490Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/espressif/ESP8266_NONOS_SDK"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/espressif/ESP8266_RTOS_SDK"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/espressif/esp-idf"
    },
    {
      "type": "FIX",
      "url": "https://lbsfilm.at/blog/wpa2-authenticationmode-downgrade-in-espressif-microprocessors"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}