CVE-2021-47232
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk46th percentile - higher than 46% of all known CVEs
Summary
In the Linux kernel, the CAN J1939 subsystem has a Use-after-Free vulnerability. The issue is that a skb is taken from the session queue without incrementing the ref count, which can lead to use-after-free if the skb is concurrently taken from the queue due to a CTS.
Risk Assessment
An attacker could exploit this vulnerability to gain unauthorized access to kernel memory, potentially leading to privilege escalation or system crash.
Recommendation
It is recommended to immediately update the Linux kernel to a version containing the fix that increments the skb ref count before use.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: can: j1939: fix Use-after-Free, hold skb ref while in use This patch fixes a Use-after-Free found by the syzbot. The problem is that a skb is taken from the per-session skb queue, without incrementing the ref count. This leads to a Use-after-Free if the skb is taken concurrently from the session queue due to a CTS.