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Review reviewCritical

CVE-2023-54203

Linux

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is called. The issue occurs while handling smb1 negotiate as smb2 server operations. Add smb server operations for smb1 (get_cmd_val, init_rsp_hdr, allocate_rsp_buf, check_user_session) to handle smb1 negotiate so that smb2 server operation does not handle it. [ 411.400423] CIFS: VFS: Use of the less secure dialect ve...

CVSS
9.1
EPSS
0.47%
38.6% percentile
CISA KEV
Not listed
Published
2025.12.30
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.47%
Technical severityCVSS 9.1

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is called. The issue occurs while handling smb1 negotiate as smb2 server operations. Add smb server operations for smb1 (get_cmd_val, init_rsp_hdr, allocate_rsp_buf, check_user_session) to handle smb1 negotiate so that smb2 server operation does not handle it. [ 411.400423] CIFS: VFS: Use of the less secure dialect ve...

Affected product and versions

Product
Linux
Affected versions
>= 51a8534c0f35c0401e45f1055f914729cad98bf9 < 921536046bd165efeb07beef5630aff35cd6a489, >= 0b3ec5671ac06829ccebdaeec05acedfec327f42 < a8334a0c535d0f0b4d64926c8fe0922ed98f7d43, >= cc32cd98a0aee4cc3eb611cbce11795b1aaa738a < 99a51c673b1d2d0b5a972353401b77612d9cc713, >= 39b291b86b5988bf8753c3874d5c773399d09b96 < dc8289f912387c3bcfbc5d2db29c8947fa207c11, >= 5.15.105 < 5.15.145, >= 6.1.22 < 6.1.24, >= 6.2.9 < 6.2.11
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CWE
Not available
CVE-2023-54203 — Linux | SECUFOCUS NOW