CVE-2023-53153 in Linux
Summary
by MITRE • 09/15/2025
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: Fix use after free for wext
Key information in wext.connect is not reset on (re)connect and can hold data from a previous connection.
Reset key data to avoid that drivers or mac80211 incorrectly detect a WEP connection request and access the freed or already reused memory.
Additionally optimize cfg80211_sme_connect() and avoid an useless schedule of conn_work.
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Analysis
by VulDB Data Team • 01/10/2026
This vulnerability exists within the linux kernel's wireless subsystem, specifically in the cfg80211 configuration interface that handles wireless network connections. The issue manifests as a use-after-free condition that occurs when processing wireless connection requests through the wireless extensions (wext) interface. When a wireless device attempts to connect or reconnect to a network, the key information structure used to store connection parameters is not properly reset between connection attempts. This oversight allows stale data from a previous connection to persist in memory locations that are subsequently reused or freed during the connection process. The vulnerability specifically affects the wext.connect functionality where connection parameters are not properly cleared, creating a scenario where drivers or the mac80211 subsystem might incorrectly interpret the stale data as a new WEP connection request.
The technical flaw stems from improper memory management practices within the wireless configuration subsystem. When a wireless connection is established or re-established, the kernel fails to properly zero out or reset key data structures that contain authentication parameters, encryption keys, or other connection metadata. This memory corruption occurs because the system does not distinguish between connection contexts, allowing data from one connection attempt to leak into subsequent operations. The improper handling of these structures creates a race condition where freed memory locations contain remnants of previous connection data that can be accessed by the wireless subsystem during new connection attempts. This represents a classic use-after-free vulnerability as defined by CWE-416, where memory is accessed after it has been freed, potentially leading to unpredictable behavior or security exploits.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates potential security risks within wireless network environments. Attackers could potentially exploit this condition to manipulate wireless connection parameters, potentially bypassing security checks or gaining unauthorized access to wireless networks. The vulnerability affects the integrity of wireless connection handling within the kernel, which could lead to denial of service conditions or unauthorized network access. When drivers or mac80211 subsystem incorrectly interpret stale connection data as a new WEP connection request, it could result in improper authentication handling or memory access violations. This type of vulnerability is particularly concerning in wireless environments where multiple connection attempts occur frequently, as the probability of triggering the use-after-free condition increases with connection frequency.
The fix implemented addresses both the core memory management issue and optimizes the underlying connection handling code. The solution involves resetting key data structures to ensure that no stale information persists between connection attempts, preventing the drivers or mac80211 subsystem from accessing freed memory locations. Additionally, the patch optimizes the cfg80211_sme_connect() function by eliminating unnecessary scheduling of the conn_work thread, reducing system overhead and potential timing issues. This optimization prevents redundant processing while ensuring proper memory cleanup occurs before new connection attempts. The mitigation aligns with best practices for secure memory management and follows established patterns for wireless subsystem security. This vulnerability affects all linux kernel versions that include the affected cfg80211 implementation and requires kernel updates to fully remediate the issue. The fix demonstrates proper adherence to memory lifecycle management principles and addresses both the immediate security concern and performance implications of the flawed implementation. This type of vulnerability would typically be categorized under the attack pattern of privilege escalation or information disclosure in the MITRE ATT&CK framework, as it could potentially allow unauthorized access to wireless network resources through memory corruption attacks.