CVE-2020-13594
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe Bluetooth Low Energy (BLE) controller implementation in Espressif ESP-IDF 4.2 and earlier (for ESP32 devices) does not properly restrict the channel map field of the connection request packet on reception, allowing attackers in radio range to cause a denial of service (crash) via a crafted packet.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe BLE controller in Espressif ESP-IDF 4.2 and earlier fails to validate the channel map field in incoming connection request packets. A malformed channel map in a crafted BLE connection request packet can trigger a crash in the ESP32's BLE stack, allowing nearby attackers to cause denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 4.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify ESP-IDF version used in firmwareCheck your project's version.h or sdkconfig.h files, or run 'idf.py --version' in your ESP-IDF project directory. Alternatively, check the release notes or build logs for the ESP-IDF version used during compilation.Affected if The ESP-IDF version is 4.2 or earlier (versions 4.3 and later contain the fix)
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Confirm BLE functionality is enabledReview your project's sdkconfig file for CONFIG_BT_ENABLED=y, or check if your code includes any BLE initialization (esp_bt_controller_init, esp_bluedroid_init, or similar BLE stack calls).Affected if BLE is enabled in the firmware configuration
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Determine BLE server role is in useInspect your firmware code for BLE advertising or connection acceptance functions such as esp_ble_gap_register_callback, esp_ble_gap_start_advertising, or esp_ble_gatt_server_register. These indicate the device accepts incoming BLE connections.Affected if The firmware acts as a BLE slave/server that accepts connections (this is required to process incoming connection request packets containing the malformed channel map)
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Check for BLE controller crashes or resetsMonitor the device via serial console or logging system for repeated BLE controller error messages, unexpected reboots, or stack traces related to BLE (keywords: BLE controller, HCI, gap, bluedroid). Review any crash logs for patterns consistent with channel map parsing failures.Affected if The device exhibits unexplained BLE stack crashes or spontaneous resets when BLE is active and receiving connections
You are affected if your ESP-IDF version is 4.2 or earlier, BLE is enabled, and your firmware acts as a BLE server that accepts incoming connections (the malformed channel map is only processed when receiving connection requests).
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate ESP-IDF to version 4.3 or later to obtain the patched BLE controller, then recompile and reflash all affected ESP32 firmware deployments.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-13594 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-13594 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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