CVE-2024-40929 in Linux
Summary
by MITRE • 07/12/2024
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mvm: check n_ssids before accessing the ssids
In some versions of cfg80211, the ssids poinet might be a valid one even though n_ssids is 0. Accessing the pointer in this case will cuase an out-of-bound access. Fix this by checking n_ssids first.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 09/17/2025
The vulnerability identified as CVE-2024-40929 affects the Linux kernel's wireless subsystem, specifically within the iwlwifi driver implementation for Intel wireless network adapters. This issue resides in the mac80211 subsystem's management virtualization module where the driver handles wireless network configuration operations. The flaw represents a classic out-of-bounds memory access condition that could potentially be exploited to disrupt system operation or potentially escalate privileges depending on the execution context.
The technical root cause of this vulnerability stems from improper input validation within the wireless configuration handling code. When processing wireless network configuration requests, the system receives a pointer to a structure containing service set identifiers along with a count parameter indicating the number of valid SSIDs. The code fails to validate that the count parameter n_ssids is greater than zero before attempting to access the ssids pointer. This oversight creates a scenario where a null or invalid pointer dereference can occur, leading to memory corruption and potential system instability.
This vulnerability specifically impacts systems running Linux kernels that include the iwlwifi driver with affected versions of the cfg80211 subsystem. The operational impact extends beyond simple system crashes to potentially enable privilege escalation attacks or denial of service conditions that could affect wireless connectivity for extended periods. The issue is particularly concerning in enterprise environments where wireless infrastructure stability is critical, as it could be exploited to disrupt network operations or create persistent access points for further attacks.
The fix implemented addresses the core validation issue by introducing a proper bounds check before accessing the SSID array. This remediation aligns with established security practices and follows the principle of input validation that prevents unauthorized memory access patterns. The solution directly corresponds to CWE-129, which describes improper validation of array index, and CWE-787, which covers out-of-bounds write operations. From an ATT&CK perspective, this vulnerability could be leveraged as part of a broader attack chain under techniques such as privilege escalation and denial of service.
Organizations should prioritize applying the kernel updates that contain this fix to protect against potential exploitation. The vulnerability demonstrates the importance of proper input validation in kernel space operations where memory corruption can lead to severe security implications. Security teams should monitor for any exploitation attempts targeting this specific kernel vulnerability and ensure comprehensive patch management processes are in place to address similar issues in other kernel subsystems. The fix represents a straightforward validation check that prevents the problematic memory access pattern while maintaining the intended functionality of the wireless configuration subsystem.