CVE-2021-47251 mac80211: fix skb length check in ieee80211_scan_rx()
A missing dynamic header length check in the Linux kernel's mac80211 subsystem can trigger a warning, potentially leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47251?
CVE-2021-47251 is a high-severity denial of service vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
mac80211: fix skb length check in ieee80211_scan_rx()
Replace hard-coded compile-time constants for header length check with dynamic determination based on the frame type. Otherwise, we hit a validation WARN_ON in cfg80211 later.
[style fixes, reword commit message]
Weakness: CWE-1284
Which versions are affected by CVE-2021-47251?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47251?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-47251 being exploited?
There is no known exploitation of CVE-2021-47251 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47251, GHSA-grwp-8243-xpjh, UBUNTU-CVE-2021-47251.