Summary
Impact: Remote Code Execution. Microsoft rating: Critical. Not known to be exploited — Exploitation More Likely. Customer action: Required.
Details
How could an attacker exploit this vulnerability?
This vulnerability is remotely triggerable by a malicious Hyper-V guest that sends an ipv6 ping to the Hyper-V host. An attacker could send a specially crafted TCPIP packet to its host utilizing the TCPIP Protocol Stack (tcpip.sys) to process packets.
This attack is specific to Hyper-V. Systems that do not have Hyper-V installed are not at risk.
Yes. Disabling IPV6 will block the threat vector. See Guidance for configuring IPv6 in Windows for advanced users for instructions for disabling IPV6.
Security updates
10.0.17763.2114 — https://support.microsoft.com/help/5005030
10.0.18363.1734 — https://support.microsoft.com/help/5005031
10.0.19043.1165 — https://support.microsoft.com/help/5005033
10.0.10240.19022 — https://support.microsoft.com/help/5005040
10.0.14393.4583 — https://support.microsoft.com/help/5005043
6.1.7601.25685 — https://support.microsoft.com/help/5005088
6.1.7601.25685 — https://support.microsoft.com/help/5005089
6.3.9600.20094 — https://support.microsoft.com/help/5005076
6.3.9600.20094 — https://support.microsoft.com/help/5005106
6.0.6003.21192 — https://support.microsoft.com/help/5005090
6.0.6003.21192 — https://support.microsoft.com/help/5005095
6.2.9200.23435 — https://support.microsoft.com/help/5005099
6.2.9200.23435 — https://support.microsoft.com/help/5005094
Vulnerabilities 1
-
Critical 9.9CVE-2021-26424 EPSS 61%
Windows TCP/IP Remote Code Execution Vulnerability
Windows TCP/IP Remote Code Execution Vulnerability
Revision history
-
#2
Updated FAQ information. This is an informational change only.
-
#1
Information published.
References
-
CVE-2021-26424 Windows TCP/IP Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26424
-
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
-
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
-
Common Vulnerability Scoring System
https://www.first.org/cvss