CVE-2021-37604

What it is

In version 6.5 of Microchip MiWi software and all previous versions including legacy products, there is a possibility of frame counters being validated/updated prior to the message authentication. With this vulnerability in place, an attacker may increment the incoming frame counter values by injecting messages with a sufficiently large frame counter value and invalid payload. This results in denial of service/valid packets in the network. There is also a possibility of a replay attack in the stack.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

1.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-08-05 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:00 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.2% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-08-05 16:15 UTC

Last modified

2026-06-17 04:00 UTC

Exploit probability

1.2% · EPSS, next 30 days

Weakness

CWE-670

Record status

Modified

Affected

• Microchip Miwi 6.5

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-37604.md and follow it. Check whether this project is affected by CVE-2021-37604. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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