CVE-2024-42483
About
ESP-NOW Component provides a connectionless Wi-Fi communication protocol. An replay attacks vulnerability was discovered in the implementation of the ESP-NOW because the caches is not differentiated by message types, it is a single, shared resource for all kinds of messages, whether they are broadcast or unicast, and regardless of whether they are ciphertext or plaintext. This can result an attacker to clear the cache of its legitimate entries, there by creating an opportunity to re-inject previously captured packets. This vulnerability is fixed in 2.5.2.
Rainforest analyst review
ESP-NOW, Espressif's connectionless Wi-Fi protocol, uses a single shared cache for every message type instead of separating them, and that lets an attacker flush the cache of legitimate entries and re-inject previously captured packets. It's a replay weakness: the protections that should make an old packet stale can be knocked out, so captured traffic can be replayed as if fresh. The impact is on integrity, not confidentiality or uptime.
The natural gate here is physical: ESP-NOW is a radio protocol, so an attacker has to be within wireless range to capture and replay, which is an adjacency requirement rather than internet reach. That makes this a concern for the local RF environment around embedded devices — think physical proximity to the deployment — rather than something exploited remotely at scale.
For us this is firmware-inventory work across an embedded fleet. The relevant question is which of our devices use ESP-NOW and whether their firmware predates the fix, since these components are easy to lose track of once deployed in the field. We weigh it by physical exposure: devices in controlled locations carry less risk than those an attacker can physically approach, and we prioritize firmware updates for the latter.
References
Related CVEs
Frequently asked questions
What is CVE-2024-42483?
ESP-NOW Component provides a connectionless Wi-Fi communication protocol. An replay attacks vulnerability was discovered in the implementation of the ESP-NOW because the caches is not differentiated by message types, it is a single, shared resource for all kinds of messages, whether they are broadcast or unicast, and regardless of whether they are ciphertext or plaintext.
How severe is CVE-2024-42483?
CVE-2024-42483 carries a CVSS 3.1 base score of 6.5, rated medium. On the Rainforest Risk Index — which weighs the severity alongside how easy the flaw is to reach and how broad its impact is — it scores 64 out of 100, in the elevated band.
How is CVE-2024-42483 exploited?
According to the CVSS vector (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N): attack vector Adjacent, attack complexity Low, privileges required None, user interaction None. Impact on confidentiality None, integrity High and availability None.
Which products are affected by CVE-2024-42483?
Public advisories list the following as affected: esp-now. Check the references on this page for the exact versions each vendor confirms.
How do I fix CVE-2024-42483?
Apply the fix the vendor published — the references on this page link to the primary advisories and patches. When patching can't happen right away, reduce the exposure of the affected component and watch it for exploitation attempts. Rainforest customers see this vulnerability correlated to their own assets and prioritized by real exposure, not by score alone.
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