CVE-2023-53384: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53384 is a NULL pointer dereference vulnerability in the Linux kernel's mwifiex WiFi driver. It affects the mwifiex_handle_uap_rx_forward() function, where the return value of skb_copy() is not checked before use in mwifiex_uap_queue_bridged_pkt(), potentially leading to a kernel crash. The vulnerability was discovered by the Linux Verification Center (linuxtesting.org) using the SVACE static analysis tool and was publicly disclosed on September 18, 2025. It affects Linux kernel versions from 3.7 through multiple stable branches up to 6.5.x. The CVSS v3.1 base score is 5.5 (Medium) (Feedly, NVD).

The root cause is classified as CWE-476 (NULL Pointer Dereference). In mwifiex_handle_uap_rx_forward(), the kernel's skb_copy() function can return NULL when memory allocation fails, but the code does not validate this return value before passing the result to mwifiex_uap_queue_bridged_pkt(), which then dereferences the NULL pointer. Exploitation requires local access with low-level privileges (e.g., a standard user account on a system using the mwifiex driver in UAP/access point mode). The fix adds a NULL check after skb_copy() and drops the original socket buffer on copy failure (NVD, Feedly).

Successful exploitation causes a kernel NULL pointer dereference, resulting in a system crash (kernel panic) and denial of service. The impact is limited to availability — there is no confidentiality or integrity impact. The vulnerability affects any Linux system running the mwifiex driver in UAP (access point) mode, and exploitation requires only local, low-privileged access, making it a realistic threat in multi-user environments (NVD, Feedly).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.033%, indicating a very low probability of exploitation in the near term (Feedly).

Patches have been applied to multiple stable Linux kernel branches. Users should update to the following fixed versions or later: 4.14.326, 4.19.295, 5.4.257, 5.10.195, 5.15.132, 6.1.53, 6.4.16, 6.5.3, or 6.6+. For systems that cannot be immediately patched, consider restricting local user access, avoiding use of the mwifiex driver in UAP mode, or applying additional kernel security hardening (e.g., kernel lockdown, seccomp). Patch commits are available via the upstream kernel stable tree (NVD, Red Hat Bugzilla).