Microsoft PowerShell Spoofing Vulnerability

published 2021-12-15 4 y ago modified 2026-09-08 2 mo ago also BIT-powershell-2021-43896 , EUVD-2021-30758

cvss: 5.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 2.5%; EPSS 2.5% chance of exploitation in 30 days, percentile 84%
public exploits: 0; none known

Patch / fix

fixed in 4 distros 1 links 1

bitnami powershell 7.2.1
Microsoft CBL Mariner 1.0 x64 7.2.1-1
Microsoft CBL Mariner 1.0 ARM 7.2.1-1
Microsoft PowerShell 7.2 7.2.1

powershell CBL-Mariner 2.0 7.2.1-1

azure linux advisories AZL-7049

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43896 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-07-18)

Exploit prediction

2.45% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N
OSV	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
bitnami	powershell	>=7.2.0, <7.2.1	7.2.1

Affected products

Microsoft CBL Mariner 2.0 x64
Microsoft CBL Mariner 2.0 ARM
Microsoft CBL Mariner 1.0 x64
Microsoft CBL Mariner 1.0 ARM
Microsoft PowerShell 7.2

References

portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2021-43896
patch, vendor-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2021-43896
web

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary