Canonical ksmbd-tools LSARPC Heap-based Buffer Overflow Remote Code Execution Vulnerability

May 17th, 2023
ZDI-23-687 ZDI-CAN-17770

CVE ID

CVSS Score

9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors

Canonical

Affected Products

ksmbd-tools

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Canonical ksmbd-tools. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the processing of the LSARPC_OPNUM_LOOKUP_SID2 opcode. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of root.

Additional Details

Fixed in 3.4.8 https://github.com/cifsd-team/ksmbd-tools/releases/tag/3.4.8


Disclosure Timeline

  • 2022-07-26 - Vulnerability reported to vendor
  • 2023-05-17 - Coordinated public release of advisory

Credit

Arnaud Gatignol, Quentin Minster, Florent Saudel, Guillaume Teissier (@thalium_team)

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