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Fencer Vulns
critical 9.8

CVE-2023-52440 in the critical feed json

ksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()

published 2024-02-21 2 y ago modified 2026-08-15 2 mo ago also EUVD-2023-57065

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
22.3%
EPSS 22.3% chance of exploitation in 30 days, percentile 97%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()

If authblob->SessionKey.Length is bigger than session key size(CIFS_KEY_SIZE), slub overflow can happen in key exchange codes. cifs_arc4_crypt copy to session key array from SessionKey from client.

Patch / fix

  • Linux Linux 6.1.52, 6.4.15, 6.5.2, 6.6
  • linux Debian 12 6.1.52-1
  • linux Debian 14, Debian 13 6.5.3-1

debian advisories DEBIAN-CVE-2023-52440

  • linux-oem-6.5 Ubuntu 22.04 LTS 6.5.0-1004.4

ubuntu advisories UBUNTU-CVE-2023-52440

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

22.34% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.