# CVE-2025-52471: ESP-NOW Integer Underflow Vulnerability Advisory

> An integer underflow in ESP-IDF's ESP-NOW protocol allows remote attackers to execute arbitrary code on IoT devices via crafted packets.

- **Severity:** High 7.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jun 2025
- **Updated:** 24 Jun 2025
- **Also known as:** GHSA-hqhh-cp47-fv5g

## What is CVE-2025-52471?

CVE-2025-52471 is a high-severity vulnerability in espressif esp-idf, published on 24 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. An integer underflow vulnerability has been identified in the ESP-NOW protocol implementation within the ESP Wi-Fi component of versions 5.4.1, 5.3.3, 5.2.5, and 5.1.6 of the ESP-IDF framework. This issue stems from insufficient validation of user-supplied data length in the packet receive function. Under certain conditions, this may lead to out-of-bounds memory access and may allow arbitrary memory write operations. On systems without a memory protection scheme, this behavior could potentially be used to achieve remote code execution (RCE) on the target device. In versions 5.4.2, 5.3.4, 5.2.6, and 5.1.6, ESP-NOW has added more comprehensive validation logic on user-supplied data length during packet reception to prevent integer underflow caused by negative value calculations. For ESP-IDF v5.3 and earlier, a workaround can be applied by validating that the `data_len` parameter received in the RX callback (registered via `esp_now_register_recv_cb()`) is a positive value before further processing. For ESP-IDF v5.4 and later, no application-level workaround is available. Users are advised to upgrade to a patched version of ESP-IDF to take advantage of the built-in mitigation.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2025-52471?

It affects 1 product.


Products: Espressif Esp-Idf.

## How do I fix CVE-2025-52471?

No fix has been published for CVE-2025-52471 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-52471 being exploited?

There is no known exploitation of CVE-2025-52471 in the wild and no public exploit code.

## Other vulnerabilities in espressif esp-idf

- [CVE-2026-45328](https://insights.sbomify.com/CVE-2026-45328/): ESF-IDF: Out-of-Bounds Write in ESP-TEE Secure Service Wrappers (critical 9.3)
- [CVE-2024-53406](https://insights.sbomify.com/CVE-2024-53406/): Auth bypass in n/a (high 8.8)
- [CVE-2021-28139](https://insights.sbomify.com/CVE-2021-28139/): Memory corruption in n/a (high 8.8)
- [CVE-2024-33453](https://insights.sbomify.com/CVE-2024-33453/): Information disclosure in n/a (high 8.1)
- [CVE-2019-12587](https://insights.sbomify.com/CVE-2019-12587/): Weak cryptography in n/a (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-52471 and fix it if it is affected.

What it is: CVE-2025-52471 is a high-severity vulnerability in espressif esp-idf, published on 24 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-52471 in the wild and no public exploit code.

Affected product: espressif esp-idf. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-52471/ (Markdown: https://insights.sbomify.com/CVE-2025-52471/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-52471
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-52471
- OSV: https://osv.dev/vulnerability/CVE-2025-52471

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-52471/
Summaries are generated and may contain mistakes; the official description above is the record.