Linux Kernel up to 5.15.1 ni_usb6501 ni6501_port_command null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.15.1 and classified as critical. Affected by this vulnerability is the function ni6501_port_command of the component ni_usb6501. Such manipulation leads to null pointer dereference. This vulnerability is uniquely identified as CVE-2021-47476. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.15.1 and classified as critical. Affected by this issue is the function ni6501_port_command of the component ni_usb6501. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

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().

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-47476 since 05/22/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 250064 (Linux Distros Unpatched Vulnerability : CVE-2021-47476), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.4.292, 4.9.290, 4.14.255, 4.19.217, 5.4.159, 5.10.79, 5.14.18 or 5.15.2 eliminates this vulnerability. Applying the patch 58478143771b/aa3973842350/df7b1238f3b5/bc51111bf6e8/b0156b7c9649/ef143dc0c3de/4a9d43cb5d5f/d6a727a681a3/907767da8f3a is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (250064). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 250064
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2021-47476

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.4.292/4.9.290/4.14.255/4.19.217/5.4.159/5.10.79/5.14.18/5.15.2
Patch: 58478143771b/aa3973842350/df7b1238f3b5/bc51111bf6e8/b0156b7c9649/ef143dc0c3de/4a9d43cb5d5f/d6a727a681a3/907767da8f3a

Timelineinfo

05/22/2024 🔍
05/22/2024 +0 days 🔍
05/22/2024 +0 days 🔍
08/17/2025 +452 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47476 (🔍)
GCVE (CVE): GCVE-0-2021-47476
GCVE (VulDB): GCVE-100-265892

Entryinfo

Created: 05/22/2024 11:39
Updated: 08/17/2025 15:55
Changes: 05/22/2024 11:39 (58), 08/17/2025 15:55 (3)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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