CVE-2021-47251: 
Linux Kernel vulnerability analysis and mitigation

In the Linux kernel, a vulnerability (CVE-2021-47251) was identified in the mac80211 subsystem's ieee80211_scan_rx() function. The issue involves improper header length checks that use hard-coded compile-time constants instead of dynamic determination based on frame type (Kernel Git).

The vulnerability exists in the ieee80211_scan_rx() function where hard-coded compile-time constants were used for header length validation instead of dynamically determining the length based on the frame type. This could result in a validation WARN_ON in cfg80211 later in the execution. The issue was introduced by commit cd418ba63f0c ("mac80211: convert S1G beacon to scan results") (Kernel Git).

When exploited, this vulnerability could lead to improper validation of frame headers in the wireless networking stack, potentially causing system warnings or validation failures (Red Hat).

The vulnerability requires the attacker to have access to the wireless network interface and the ability to send specially crafted frames. No known exploits have been reported in the wild (NVD).

The vulnerability has been fixed by replacing the hard-coded compile-time constants with dynamic header length determination based on the frame type. Users should update their Linux kernel to a version that includes the fix (Kernel Git).