CVE-2021-47611: 
Linux Kernel vulnerability analysis and mitigation

CVE-2021-47611 is a vulnerability in the Linux kernel's mac80211 subsystem, discovered and disclosed in June 2024. The vulnerability affects the handling of extended element IDs in wireless networking functionality. The issue affects multiple versions of the Linux kernel, including versions from 4.19 through 5.16-rc5 (NVD).

The vulnerability stems from a failure to validate the presence of an extended element ID before attempting to parse it in the mac80211 subsystem. This issue was introduced in commit 41cbb0f5a295 ('mac80211: add support for HE'). The vulnerability has been assigned a CVSS v3.1 base score of 5.5 (Medium), with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (NVD).

The vulnerability could potentially lead to system availability issues when processing malformed wireless network packets. The CVSS scoring indicates that while there is no impact on confidentiality or integrity, there is a high impact on availability of the affected system (NVD).

The vulnerability requires local access with low privileges and no user interaction to exploit. The attack complexity is considered low, indicating that the vulnerability is relatively straightforward to exploit under the right conditions (NVD).

The vulnerability has been fixed through a patch that adds validation of the extended element ID before parsing. The fix has been implemented across multiple kernel versions. The patch verifies that the extended element ID is present before attempting to parse an extended element (Kernel Patch).