PT-2021-2423 · Microsoft · Windows

Somaro · Published 2021-03-09 · Updated 2024-04-29 · CVE-2021-26887

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: Microsoft Windows (affected versions not specified)

Description: The issue is related to the implementation of the Folder Redirection technology in Microsoft Windows, which is associated with insecure privilege management. An attacker who successfully exploits this issue could gain elevated privileges, allowing them to redirect another user's personal data to a created folder. This can be achieved by creating a new folder under the Folder Redirection root path and creating a junction on a newly created User folder. When a new user logs in, Folder Redirection would start redirecting to the folder and copying personal data.

Recommendations: To address this issue, reconfigure Folder Redirection with Offline files and restrict permissions. This can be done by following the configuration guidance provided. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

LPE

Improper Privilege Management

Link Following

Weakness Enumeration

CWE-269

CWE-59

Related Identifiers

BDU:2021-01677

CVE-2021-26887

Affected Products

Windows

References · 11

• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2021-26887 · Vendor Advisory
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26887 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-26887 · Security Note
• https://bdu.fstec.ru/vul/2021-01677 · Security Note
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26887 · Security Note
• https://osv.dev/vulnerability/CVE-2021-26887 · Vendor Advisory
• https://github.com/potmdehex/multicast_bytecopy · Note
• https://twitter.com/buaqbot/status/1785192409325818191 · Twitter Post
• https://t.me/cybersecuritytechnologies/5899 · Telegram Post
• https://t.me/pentestingnews/22395 · Telegram Post
• https://t.me/cvenotify/11288 · Telegram Post