CVE-2020-16146
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 · uneditedEspressif ESP-IDF 2.x, 3.0.x through 3.0.9, 3.1.x through 3.1.7, 3.2.x through 3.2.3, 3.3.x through 3.3.2, and 4.0.x through 4.0.1 has a Buffer Overflow in BluFi provisioning in btc_blufi_recv_handler function in blufi_prf.c. An attacker can send a crafted BluFi protocol Write Attribute command to characteristic 0xFF01. With manipulated packet fields, there is a buffer overflow.
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 confidenceA buffer overflow vulnerability exists in the BluFi provisioning component of Espressif ESP-IDF. The issue is in the btc_blufi_recv_handler function in blufi_prf.c. Attackers can exploit this by sending a crafted BluFi protocol Write Attribute command to Bluetooth characteristic 0xFF01 with manipulated packet fields that overflow a buffer, potentially enabling remote code execution or 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>= 2.0.0, <= 2.1.1>= 3.0, <= 3.0.9>= 3.1, <= 3.1.7>= 3.2, <= 3.2.3>= 3.3, <= 3.3.2>= 4.0.0, <= 4.0.1CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/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 in firmwareExtract and examine the firmware binary, looking for ESP-IDF version strings in the binary metadata, or check project build configuration files (e.g., sdkconfig, version.h) if you have access to the build environmentAffected if The identified version falls within any of these ranges: 2.0.0-2.1.1, 3.0-3.0.9, 3.1-3.1.7, 3.2-3.2.3, 3.3-3.3.2, or 4.0.0-4.0.1
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Verify BluFi provisioning is enabledCheck the ESP-IDF project configuration (sdkconfig) for CONFIG_BLUFI_ENABLED=y, or search the firmware binary for BluFi-related strings and the characteristic UUID 0xFF01Affected if BluFi provisioning feature is compiled into the firmware (CONFIG_BLUFI_ENABLED is set)
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Confirm Bluetooth is active on the deviceInspect the device configuration or firmware for Bluetooth stack initialization (look for CONFIG_BT_ENABLED=y in sdkconfig, or check for BLE stack strings in the firmware)Affected if Bluetooth (BLE) is enabled in the firmware configuration
The device is affected if it runs ESP-IDF within the vulnerable version ranges AND has BluFi provisioning compiled in AND has Bluetooth enabled, making the 0xFF01 characteristic reachable over the air.
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 a patched version (3.0.10+, 3.1.8+, 3.2.4+, 3.3.3+, 4.0.2+) and recompile/redeploy firmware to all affected IoT devices. If updating is not immediately feasible, restrict Bluetooth access to trusted devices and monitor for anomalous BluFi traffic.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2020-16146 — 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-2020-16146 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
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