Linux Kernel (< 6.6.5, 6.7) - CraftedSignal Threat Feedhttps://feed.craftedsignal.io/products/linux-kernel--6.6.5-6.7/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioFri, 23 Oct 2026 19:48:50 +0000https://feed.craftedsignal.io/favicon-32x32.pngCraftedSignal Threat Feedhttps://feed.craftedsignal.io/3232https://feed.craftedsignal.io/favicon.svgLinux Kernel: io_uring privilege escalation (CVE-2024-0582)https://feed.craftedsignal.io/briefs/2026-10-linux-kernel-lpe/Fri, 23 Oct 2026 19:48:50 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-10-linux-kernel-lpe/CVE-2024-0582 is a privilege escalation vulnerability in the Linux kernel io_uring subsystem that enables unauthorized write access to /etc/passwd via a Dirty Cred technique.A proof-of-concept exploit for CVE-2024-0582 has been published, targeting a use-after-free vulnerability within the Linux kernel io_uring subsystem during buffer ring unregistration. The exploit utilizes a "Dirty Cred" approach to corrupt kernel structures, specifically modifying the f_mode flags of file descriptors to grant write access to protected files, including /etc/passwd. Successful exploitation allows a local attacker to escalate privileges to root by injecting a backdoor entry into /etc/passwd.

Attack Chain

  1. Set CPU affinity and raise file descriptor limits to ensure exploit stability.
  2. Initialize an io_uring instance and register a buffer ring in kernel memory.
  3. Unregister the buffer ring to trigger the use-after-free vulnerability.
  4. Perform a file descriptor spray to target the /etc/passwd file descriptor.
  5. Corrupt the f_mode flags of the target file descriptor to make /etc/passwd writable.
  6. Append a custom root user backdoor entry to /etc/passwd.

Impact

Successful exploitation grants a local user full root privileges. The exploit requires local access and can be used to bypass system integrity by modifying sensitive configuration files.

Recommendation

  • Audit kernel versions across the environment to identify systems running Linux Kernel versions < 6.6.5 or 6.7.
  • Prioritize patching affected Linux kernels to the latest available stable release.
  • Deploy monitoring for unauthorized or anomalous modifications to /etc/passwd.
  • Restrict the use of io_uring for non-privileged users if the workload allows, as it is a common vector for local privilege escalation.
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