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CVE-2024-30088Exploited in the wildNVD status: Analyzed

Microsoft Windows Kernel TOCTOU Race Condition

Published Updated By the CyberSecBulletin desk

CVE-2024-30088 is a high-severity time-of-check time-of-use (TOCTOU) race condition vulnerability in Windows 10 Version 1507 from Microsoft, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 10.0.10240.20680 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 October 15, 2024, 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 10.0.10240.20680 or a later version.
  2. Update Windows 10 Version 1607 to 10.0.14393.7070 or a later version.
  3. Update Windows 10 Version 1809 to 10.0.17763.5936 or a later version.
  4. CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  5. Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
MicrosoftWindows 10 Version 150710.0.10240.0 up to, but not including, 10.0.10240.2068010.0.10240.20680
MicrosoftWindows 10 Version 160710.0.14393.0 up to, but not including, 10.0.14393.707010.0.14393.7070
MicrosoftWindows 10 Version 180910.0.17763.0 up to, but not including, 10.0.17763.5936; 10.0.0 up to, but not including, 10.0.17763.593610.0.17763.5936
MicrosoftWindows 10 Version 21H210.0.19044.0 up to, but not including, 10.0.19044.452910.0.19044.4529
MicrosoftWindows 10 Version 22H210.0.19045.0 up to, but not including, 10.0.19045.452910.0.19045.4529
MicrosoftWindows 11 version 21H210.0.22000.0 up to, but not including, 10.0.22000.301910.0.22000.3019
MicrosoftWindows 11 version 22H210.0.22621.0 up to, but not including, 10.0.22621.373710.0.22621.3737
MicrosoftWindows 11 version 23H210.0.22631.0 up to, but not including, 10.0.22631.373710.0.22631.3737
MicrosoftWindows Server 201610.0.14393.0 up to, but not including, 10.0.14393.707010.0.14393.7070
MicrosoftWindows Server 2016 (Server Core installation)10.0.14393.0 up to, but not including, 10.0.14393.707010.0.14393.7070
MicrosoftWindows Server 201910.0.17763.0 up to, but not including, 10.0.17763.593610.0.17763.5936
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 up to, but not including, 10.0.17763.593610.0.17763.5936
MicrosoftWindows Server 202210.0.20348.0 up to, but not including, 10.0.20348.252710.0.20348.2527
MicrosoftWindows Server 2022, 23H2 Edition (Server Core installation)10.0.25398.0 up to, but not including, 10.0.25398.95010.0.25398.950
MicrosoftWindows 10 1507before 10.0.10240.2068010.0.10240.20680
MicrosoftWindows 10 1607before 10.0.14393.707010.0.14393.7070
MicrosoftWindows 10 1809before 10.0.17763.593610.0.17763.5936
MicrosoftWindows 10 21h2before 10.0.19044.452910.0.19044.4529
MicrosoftWindows 10 22h2before 10.0.19045.452910.0.19045.4529
MicrosoftWindows 11 21h2before 10.0.22000.301910.0.22000.3019
MicrosoftWindows 11 22h2before 10.0.22621.373710.0.22621.3737
MicrosoftWindows 11 23h2before 10.0.22631.373710.0.22631.3737
MicrosoftWindows Server 2022 23h2before 10.0.25398.95010.0.25398.950

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Official description

Windows Kernel Elevation of Privilege Vulnerability

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

The underlying weakness: Time-of-check Time-of-use (TOCTOU) Race Condition

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

How developers prevent this class of flaw

  • The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
  • When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
  • Limit the interleaving of operations on files from multiple processes.

More Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities (CWE-367)

Timeline

  1. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  2. CVE record published.
  3. Added to CISA's Known Exploited Vulnerabilities catalogue.
  4. Deadline for US federal agencies to remediate, set by CISA.
  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 Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities

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