Vulnerability Monitor

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CVE-2020-12638

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.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.8, indicating it requires adjacent network access but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), for affected systems. Impacting 3 products from espressif, from espressif, from espressif organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2020-07-23T16:15:12.490

Last Modified

2026-06-17T02:52:02.963

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.8 (MEDIUM)

CVSSv2 Vector

AV:A/AC:M/Au:N/C:P/I:P/A:N

Access Vector: ADJACENT_NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: PARTIAL
Availability Impact: NONE

Exploitability Score

5.5

Impact Score

4.9

Weaknesses

Type: Primary
CWE-287
CWE-319

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	espressif	esp-idf	≤ 4.2	Yes
Application	espressif	esp8266_nonos_sdk	≤ 3.0.3	Yes
Application	espressif	esp8266_rtos_sdk	≤ 3.3	Yes

References

https://github.com/espressif/ESP8266_NONOS_SDK Third Party Advisory ([email protected])
https://github.com/espressif/ESP8266_RTOS_SDK Third Party Advisory ([email protected])
https://github.com/espressif/esp-idf Third Party Advisory ([email protected])
https://lbsfilm.at/blog/wpa2-authenticationmode-downgrade-in-espressif-microprocessors Exploit, Patch, Third Party Advisory ([email protected])
https://github.com/espressif/ESP8266_NONOS_SDK Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/espressif/ESP8266_RTOS_SDK Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/espressif/esp-idf Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lbsfilm.at/blog/wpa2-authenticationmode-downgrade-in-espressif-microprocessors Exploit, Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For espressif's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.