Attacker Value
Very High
(1 user assessed)
Exploitability
Unknown
(1 user assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
4

CVE-2022-26809

Disclosure Date: April 15, 2022
Add MITRE ATT&CK tactics and techniques that apply to this CVE.
Lateral Movement
Techniques
Validation
Validated

Description

Remote Procedure Call Runtime Remote Code Execution Vulnerability

Add Assessment

1
Ratings
Technical Analysis

This vulnerability is one of the three Windows RPC related issues that were fixed in Microsoft’s April 2022 Patch Tuesday. Compared to CVE-2022-24492 and CVE-2022-24528, this one does not require user interaction. It also has the highest CVSS score (9.8) and severity (Critical). Unpatched systems that expose port 445/TCP are potentially vulnerable to Remote Code Execution. This is more likely something that would happen on an internal network, since this port is usually not exposed to the Internet (well, it should not). This bug would be very interesting for any attacker that has gained access to the internal network and needs to move laterally.
According to this article, the issue seems to be an integer overflow bug. Patch diffing reveals that many calls to some kind of sanitizing function have been added. This function checks if an integer value is still in the expected range after some arithmetic operations and should avoid a potentially heap buffer overflow. These checks have been added in multiple locations, both on RPC client-side and server-side of the execution flow.

CVSS V3 Severity and Metrics
Base Score:
9.8 Critical
Impact Score:
5.9
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • microsoft

Products

  • windows 10 -,
  • windows 10 1607,
  • windows 10 1809,
  • windows 10 1909,
  • windows 10 20h2,
  • windows 10 21h1,
  • windows 10 21h2,
  • windows 11 -,
  • windows 7 -,
  • windows 8.1 -,
  • windows rt 8.1 -,
  • windows server 2008,
  • windows server 2008 r2,
  • windows server 2012 -,
  • windows server 2012 r2,
  • windows server 2016 -,
  • windows server 2016 20h2,
  • windows server 2019 -,
  • windows server 2022 -

Additional Info

Technical Analysis