CyberSecBulletin
CVE-2022-41091Exploited in the wildNVD status: Analyzed

Microsoft Windows Mark of the Web (MOTW) Security Feature Bypass

Published Updated By the CyberSecBulletin desk

CVE-2022-41091 is a medium-severity incorrect authorization vulnerability in Windows 10 Version 1507 from Microsoft, with a CVSS 3.1 base score of 5.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 10.0.10240.19567 as the first without the flaw, so updating Windows 10 Version 1507 to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on November 8, 2022, which means attacks have been observed in the wild, including in ransomware campaigns.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Windows 10 Version 1507 to 10.0.10240.19567 or a later version.
  2. Update Windows 10 Version 1607 to 10.0.14393.5501 or a later version.
  3. Update Windows 10 Version 1809 to 10.0.17763.3650 or a later version.
  4. CISA's required action: Apply updates per vendor instructions.
  5. Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
  6. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  7. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
MicrosoftWindows 10 Version 150710.0.10240.0 up to, but not including, 10.0.10240.1956710.0.10240.19567
MicrosoftWindows 10 Version 160710.0.14393.0 up to, but not including, 10.0.14393.550110.0.14393.5501
MicrosoftWindows 10 Version 180910.0.17763.0 up to, but not including, 10.0.17763.3650; 10.0.0 up to, but not including, 10.0.17763.365010.0.17763.3650
MicrosoftWindows 10 Version 20H210.0.0 up to, but not including, 10.0.19042.225110.0.19042.2251
MicrosoftWindows 10 Version 21H110.0.0 up to, but not including, 10.0.19043.225110.0.19043.2251
MicrosoftWindows 10 Version 21H210.0.19043.0 up to, but not including, 10.0.19044.225110.0.19044.2251
MicrosoftWindows 10 Version 22H210.0.19045.0 up to, but not including, 10.0.19045.225110.0.19045.2251
MicrosoftWindows 11 version 21H210.0.0 up to, but not including, 10.0.22000.121910.0.22000.1219
MicrosoftWindows 11 version 22H210.0.22621.0 up to, but not including, 10.0.22621.81910.0.22621.819
MicrosoftWindows Server 201610.0.14393.0 up to, but not including, 10.0.14393.550110.0.14393.5501
MicrosoftWindows Server 2016 (Server Core installation)10.0.14393.0 up to, but not including, 10.0.14393.550110.0.14393.5501
MicrosoftWindows Server 201910.0.17763.0 up to, but not including, 10.0.17763.365010.0.17763.3650
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 up to, but not including, 10.0.17763.365010.0.17763.3650
MicrosoftWindows Server 202210.0.20348.0 up to, but not including, 10.0.20348.124910.0.20348.1249
MicrosoftWindows 10 1507before 10.0.10240.1956710.0.10240.19567
MicrosoftWindows 10 1607before 10.0.14393.550110.0.14393.5501
MicrosoftWindows 10 1809before 10.0.17763.365010.0.17763.3650
MicrosoftWindows 10 20h2before 10.0.19042.225110.0.19042.2251
MicrosoftWindows 10 21h1before 10.0.19043.225110.0.19043.2251
MicrosoftWindows 10 21h2before 10.0.19044.225110.0.19044.2251
MicrosoftWindows 10 22h2before 10.0.19045.225110.0.19045.2251
MicrosoftWindows 11 21h2before 10.0.22000.121910.0.22000.1219
MicrosoftWindows 11 22h2before 10.0.22621.81910.0.22621.819

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L. Scored by CNA (microsoft.com).

Official description

Windows Mark of the Web Security Feature Bypass Vulnerability

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Incorrect Authorization vulnerabilities (CWE-863)

Timeline

  1. Added to CISA's Known Exploited Vulnerabilities catalogue.
  2. CVE record published.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: partial).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Windows 10 Version 1507

All Windows 10 Version 1507 vulnerabilities

Recent Incorrect Authorization vulnerabilities

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