PT-2021-3281 · Microsoft · Windows Cloud Files Mini Filter Driver+1

Keqi Hu · Published 2021-06-08 · Updated 2026-05-13 · CVE-2021-31969

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Windows Cloud Files Mini Filter Driver (affected versions not specified)

Description The vulnerability is related to errors in privilege management in the Windows Cloud Files Mini Filter Driver. It allows an attacker to elevate their privileges. The issue is associated with an integer underflow in the Windows Cloud Filter API and a kernel pool overflow from a restrictive chunk size.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

LPE

Improper Privilege Management

Weakness Enumeration

CWE-269

CWE-264

Related Identifiers

BDU:2021-03052

CVE-2021-31969

ZDI-21-797

Affected Products

Windows

Windows Cloud Files Mini Filter Driver

References · 26

• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-31969 · Security Note
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31969 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-31969 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-31969 · Security Note
• https://bdu.fstec.ru/vul/2021-03052 · Security Note
• https://zerodayinitiative.com/advisories/ZDI-21-797 · Security Note
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2021-31969 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-31969 · Vendor Advisory
• https://twitter.com/_x13/status/1830531070715969743 · Twitter Post
• https://cybersecurity-help.cz/vdb/SB2021060825 · Note
• https://t.me/pentestingnews/8081 · Telegram Post
• https://twitter.com/0xor0ne/status/1854554633655472504 · Twitter Post
• https://t.me/cvenotify/15914 · Telegram Post
• https://starlabs.sg/blog/2023/11-exploitation-of-a-kernel-pool-overflow-from-a-restrictive-chunk-size-cve-2021-31969 · Note
• https://twitter.com/reverseame/status/1843890666402722028 · Twitter Post