esp-idf: Out-of-bounds Read
CVE-2025-66409 is a critical-severity out-of-bounds read vulnerability in esp-idf from Espressif, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected esp-idf versions: >= 5.5-beta1, <= 5.5.1; >= 5.4-beta1, <= 5.4.3; >= 5.3-beta1, <= 5.3.4, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of esp-idf you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Espressif | esp-idf | >= 5.5-beta1, <= 5.5.1; >= 5.4-beta1, <= 5.4.3; >= 5.3-beta1, <= 5.3.4; >= 5.2-beta1, <= 5.2.6; <= 5.1.6 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 2.7 | Low | CNA (github.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In 5.5.1, 5.4.3, 5.3.4, 5.2.6, 5.1.6, and earlier, when AVRCP is enabled on ESP32, receiving a malformed VENDOR DEPENDENT command from a peer device can cause the Bluetooth stack to access memory before validating the command buffer length. This may lead to an out-of-bounds read, potentially exposing unintended memory content or causing unexpected behavior.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/espressif/esp-idf/commit/075ed218cadb8088155521cd8a795d8a626519fb
- github.com/espressif/esp-idf/commit/2f788e59ee361eee230879ae2ec9cf5c893fe372
- github.com/espressif/esp-idf/commit/798029129a71c802cff0e75eb59f902bca8f1946
- github.com/espressif/esp-idf/commit/999710fccf95ae128fe51b5679d6b7c75c50d902
- github.com/espressif/esp-idf/commit/d5db5f60fc1dcfdd8cd3ee898fdefaa272988ace
- github.com/espressif/esp-idf/commit/daeeba230327176b9627b1caa94acdc54065c4b7
Other vulnerabilities in esp-idf
- 7.4 High severity
- 7.1 High severity
- 9.3 Critical severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
Recent Out-of-bounds Read vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.1 High severity
- 7.4 High severity
- 7.5 High severity
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