CVE-2023-52441
A critical flaw in the Linux kernel’s SMB server (ksmbd) allows an attacker to crash the system by sending a specific sequence of SMB requests. The bug was fixed in a kernel patch that ignores SMB1 packets after the SMB2 negotiation flag is cleared. Users should update to a kernel version that includes this patch.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel, specifically the ksmbd SMB server component.
Real-world impact
An attacker could send a crafted SMB2 negotiate request followed by an SMB1 negotiate request to trigger an out‑of‑bounds memory access, causing the kernel to crash and resulting in a denial of service.
Why this severity
The CVSS score of 9.1 reflects that the vulnerability can be exploited remotely over the network (AV:N), requires no user interaction or privileges (PR:N, UI:N), and has a low attack complexity (AC:L). It fully compromises confidentiality and availability (C:H, A:H) while integrity is unaffected.
What to do about it
- 011. Identify the current Linux kernel version you are running.
- 022. Update the kernel to a version that includes the ksmbd patch for init_smb2_rsp_hdr().
- 033. Reboot the system to load the updated kernel.
NVD-referenced vendor advisory
Timeline
- Feb 21, 2024 · Feb 21, 2024PublishedDisclosed and added to the National Vulnerability Database.
- Aug 4, 2026 · 2d agoAdvisory updatedThe NVD record was last revised.
- Aug 6, 2026 · 8h agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.