CVE-2024-27397: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-27397 is a vulnerability in the Linux kernel's netfilter nf_tables component that affects versions 4.1 through 6.8. The issue specifically involves the handling of timeouts for elements within NFT sets, where elements could expire during a transaction, potentially leading to use-after-free conditions (SecurityOnline).

The vulnerability occurs in the netfilter nftables component during rollback operations involving expired elements. The issue specifically arises in the nftsetelemexpired function defined in nf_tables.h. The problem stems from asymmetric clean-up operations when elements expire during a transaction, which can result in missing reference count updates and use-after-free conditions (SecurityOnline).

The vulnerability can be exploited by a local attacker to either crash the system or escalate privileges. Testing has shown a 90%-100% success rate when Address Space Layout Randomization (ASLR) is bypassed (SecurityOnline).

The vulnerability has been patched in the Linux kernel. The fix involves adding a timestamp field at the beginning of the transaction, storing it in the nftables per-netns area, and updating set backend operations to use this timestamp. This prevents elements from expiring while control plane transactions are still unfinished (Kernel Commit). Users are strongly advised to update to the latest kernel versions that include this fix.