Linux Kernel up to 6.13.0 quatech2 qt2_process_read_urb null pointer dereference

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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.13.0. Affected by this issue is the function qt2_process_read_urb of the component quatech2. Executing a manipulation can lead to null pointer dereference. This vulnerability is registered as CVE-2025-21689. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.13.0. This vulnerability affects the function qt2_process_read_urb of the component quatech2. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb() This patch addresses a null-ptr-deref in qt2_process_read_urb() due to an incorrect bounds check in the following: if (newport > serial->num_ports) { dev_err(&port->dev, "%s - port change to invalid port: %i\n", __func__, newport); break; } The condition doesn't account for the valid range of the serial->port buffer, which is from 0 to serial->num_ports - 1. When newport is equal to serial->num_ports, the assignment of "port" in the following code is out-of-bounds and NULL: serial_priv->current_port = newport; port = serial->port[serial_priv->current_port]; The fix checks if newport is greater than or equal to serial->num_ports indicating it is out-of-bounds.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2025-21689 since 12/29/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 216985 (Debian dla-4076 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.290, 5.10.234, 5.15.178, 6.1.128, 6.6.75, 6.12.12, 6.13.1 or 6.14-rc1 eliminates this vulnerability. Applying the patch fa4c7472469d97c4707698b4c0e098f8cfc2bf22/94770cf7c5124f0268d481886829dc2beecc4507/6068dcff7f19e9fa6fa23ee03453ad6a40fa4efe/4b9b41fabcd38990f69ef0cee9c631d954a2b530/6377838560c03b36e1153a42ef727533def9b68f/f371471708c7d997f763b0e70565026eb67cc470/8542b33622571f54dfc2a267fce378b6e3840b8b/575a5adf48b06a2980c9eeffedf699ed5534fade 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 databases at Tenable (216985) and CERT Bund (WID-SEC-2025-0309). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • RESF Rocky Linux
  • Dell NetWorker
  • Dell Avamar
  • Open Source Linux Kernel
  • Dell PowerProtect Data Domain

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

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

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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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: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 216985
Nessus Name: Debian dla-4076 : linux-config-6.1 - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.4.290/5.10.234/5.15.178/6.1.128/6.6.75/6.12.12/6.13.1/6.14-rc1
Patch: fa4c7472469d97c4707698b4c0e098f8cfc2bf22/94770cf7c5124f0268d481886829dc2beecc4507/6068dcff7f19e9fa6fa23ee03453ad6a40fa4efe/4b9b41fabcd38990f69ef0cee9c631d954a2b530/6377838560c03b36e1153a42ef727533def9b68f/f371471708c7d997f763b0e70565026eb67cc470/8542b33622571f54dfc2a267fce378b6e3840b8b/575a5adf48b06a2980c9eeffedf699ed5534fade

Timelineinfo

12/29/2024 🔍
02/10/2025 +43 days 🔍
02/10/2025 +0 days 🔍
02/17/2026 +372 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-21689 (🔍)
GCVE (CVE): GCVE-0-2025-21689
GCVE (VulDB): GCVE-100-295120
CERT Bund: WID-SEC-2025-0309 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 02/10/2025 17:21
Updated: 02/17/2026 03:31
Changes: 02/10/2025 17:21 (59), 02/21/2025 19:08 (11), 03/02/2025 13:39 (2), 10/09/2025 14:50 (7), 02/17/2026 03:31 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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