---
cve: "CVE-2021-47476"
severity: "MEDIUM"
cvss: 4.6
epss: "39%"
vendor: "Linux"
kev: false
exploited: false
published: "2024-05-22 09:15:09"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-08-31T03:17:02+02:00"
---

# CVE-2021-47476

> 4.6 MEDIUM

## Beschreibung

In the Linux kernel, the following vulnerability has been resolved:

comedi: ni_usb6501: fix NULL-deref in command paths

The driver uses endpoint-sized USB transfer buffers but had no sanity
checks on the sizes. This can lead to zero-size-pointer dereferences or
overflowed transfer buffers in ni6501_port_command() and
ni6501_counter_command() if a (malicious) device has smaller max-packet
sizes than expected (or when doing descriptor fuzz testing).

Add the missing sanity checks to probe().

## CVSS-Vektor

```
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Physisch | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Referenzen

- <https://git.kernel.org/stable/c/58478143771b20ab219937b1c30a706590a59224>
- <https://git.kernel.org/stable/c/aa39738423503825625853b643b9e99d11c23816>
- <https://git.kernel.org/stable/c/df7b1238f3b599a0b9284249772cdfd1ea83a632>
- <https://git.kernel.org/stable/c/bc51111bf6e8e7b6cc94b133e4c291273a16acd1>
- <https://git.kernel.org/stable/c/b0156b7c9649d8f55a2ce3d3258509f1b2a181c3>
- <https://git.kernel.org/stable/c/ef143dc0c3defe56730ecd3a9de7b3e1d7e557c1>
- <https://git.kernel.org/stable/c/4a9d43cb5d5f39fa39fc1da438517004cc95f7ea>
- <https://git.kernel.org/stable/c/d6a727a681a39ae4f73081a9bedb45d14f95bdd1>
- <https://git.kernel.org/stable/c/907767da8f3a925b060c740e0b5c92ea7dbec440>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-47476) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_