The US Cybersecurity and Infrastructure Security Agency has issued an urgent warning about CVE-2024-1086, a critical Linux kernel vulnerability actively exploited by hackers to deploy ransomware. This use-after-free flaw allows attackers to escalate privileges to root level on affected systems. Organizations worldwide are urged to patch immediately to mitigate the threat.
The vulnerability, tracked as CVE-2024-1086, is a use-after-free issue in the netfilter component of the Linux kernel, specifically the nf_tables subsystem. It enables local privilege escalation, allowing attackers with initial access to gain root privileges and full control of compromised machines. Classified under CWE-416, the flaw stems from improper memory handling in functions like nft_verdict_init() and nf_hook_slow(), leading to memory corruption and arbitrary code execution in kernel space.
Originally introduced in the Linux kernel in 2014, CVE-2024-1086 affects versions from 3.15 through 6.8 rc1, impacting major distributions such as Debian, Ubuntu, Fedora, and Red Hat. A patch was released in January 2024, and the issue was added to CISA's Known Exploited Vulnerabilities catalog in May 2024. Security firm CrowdStrike first detected exploitation attempts in April 2024, later rating the risk as critical after public exploit code emerged online.
Ransomware operators have integrated this flaw into their attack chains to disable endpoint protections, encrypt files, delete backups, and move laterally across networks. The vulnerability's presence in widely used Linux systems heightens risks for enterprise environments, cloud infrastructure, and data centers. CISA has mandated that federal civilian executive branch agencies apply patches or discontinue use of affected systems, while recommending all organizations prioritize vulnerability management based on the KEV catalog.
Network defenders should inventory Linux systems, identify vulnerable kernels, apply updates, and review logs for signs of privilege escalation or unusual kernel activity. This active exploitation underscores the need for swift action to prevent ransomware deployment and data exfiltration.