Cloudanix VulnDB

CVE-2023-53767

None

CVSS

—

EPSS

0.2%

Published

Dec 8, 2025

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A small coding mistake in certain WiFi drivers could slowly use up memory on some computers running Ubuntu, and updating the system fixes it.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Memory leak in ath12k WiFi driver where event buffers and associated list entries are not freed when the ATH12K_FLAG_UNREGISTERING flag is set during QMI driver event processing.

Why it matters to the business

Gradual memory exhaustion on affected Ubuntu 20.04 systems using Qualcomm WiFi hardware can lead to degraded performance, instability, or service restarts over time; the issue affects widely deployed LTS kernels with high ecosystem prevalence.

How an attack unfolds

An attacker triggers repeated QMI driver events in the ath12k module while the unregistering flag is active, causing allocations without corresponding frees; no named threat actors or ransomware campaigns are associated and exploitation maturity remains none.

How to fix it

Upgrade affected packages to the listed fixed versions: linux 5.4.0-9.12, linux-aws 5.4.0-1005.5, linux-aws-5.15 5.15.0-1014.18~20.04.1, linux-azure 5.4.0-1006.6, linux-azure-5.15 5.15.0-1007.8~20.04.1, linux-azure-fde-5.15 5.15.0-1019.24~20.04.1.1, linux-bluefield 5.4.0-1007.10, linux-gcp 5.4.0-1005.5, linux-gcp-5.15 5.15.0-1006.9~20.04.1, linux-gkeop 5.4.0-1008.9, linux-gkeop-5.15 5.15.0-1003.5~20.04.2, linux-hwe-5.15 5.15.0-33.34~20.04.1, linux-ibm 5.4.0-1003.4.

How to confirm the fix worked

Confirm kernel package versions match or exceed the fixed releases above and verify absence of the original return statement without goto skip in ath12k_qmi_driver_event_work.

Typical attack path

  1. Identify systems running vulnerable ath12k driver in Linux kernel
  2. Trigger QMI driver event work under unregistering conditions
  3. Repeat to accumulate unfreed memory buffers
  4. Monitor for memory pressure or kernel OOM events

How to detect it

Review kernel logs for ath12k QMI event warnings and track process memory growth on systems with the affected driver; no specific post-exploitation artifacts are available.

What your security team should do

  • Prioritize patching Ubuntu 20.04 LTS kernels within standard maintenance windows given 325 days since publication
  • Monitor memory utilization on systems with Qualcomm ath12k hardware
  • Apply updates from official Ubuntu repositories for all listed packages

The record

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix memory leak in ath12k_qmi_driver_event_work() Currently the buffer pointed by event is not freed in case ATH12K_FLAG_UNREGISTERING bit is set, this causes memory leak. Add a goto skip instead of return, to ensure event and all the list entries are freed properly. Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1

Affected packages

Ecosystem Package Introduced Fixed
Linux Kernel 0 6.3.4
Linux Kernel 6.3.0 6.3.4

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