CVE-2021-26886: Microsoft Windows User Profile Service Directory Junction Denial-of-Service Vulnerability
User Profile Service Denial of Service Vulnerability
Other sources
This vulnerability allows local attackers to create a denial-of-service condition on affected installations of Microsoft Windows. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the User Profile Service. By creating a junction, an attacker can abuse the service to overwrite the contents of a chosen file. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.
— ZDI
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.19968Patch KB5000853 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.23298Patch KB5000840 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.19968Patch KB5000848 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.4283Patch KB5000803 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19043.867Patch KB5000802 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.10240.18874Patch KB5000807 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.18363.1440Patch KB5000808 - Upgrade
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Fixed in 10.0.17763.1817Patch KB5000822 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.17134.2087Patch KB5000809
Event History
Frequently Asked Questions
What is the severity of CVE-2021-26886?
CVE-2021-26886 has a severity rating of Medium, as it allows local attackers to create a denial-of-service condition.
How do I fix CVE-2021-26886?
To fix CVE-2021-26886, install the latest security update provided by Microsoft for your affected Windows version.
Which operating systems are affected by CVE-2021-26886?
CVE-2021-26886 affects several versions of Microsoft Windows, including various releases of Windows 10 and Windows Server.
Can CVE-2021-26886 be exploited remotely?
No, CVE-2021-26886 requires local access to exploit, making it a local denial-of-service vulnerability.
What type of vulnerability is CVE-2021-26886 classified as?
CVE-2021-26886 is classified as a denial-of-service vulnerability in the User Profile Service.