CVE-2021-31204

Privilege escalation via unsafe single-file bundle extraction

Published May 11, 2021 · Updated Aug 3, 2024

Elevation of privilege in Microsoft .NET and bundled Visual Studio SDKs allows local users to gain elevated privileges through single-file apps. The single-file host extracts bundled files into a directory without safely preserving privilege boundaries against tampering on Unix systems. Exploitation requires an affected Linux or macOS application to run with elevated permissions and can execute attacker-controlled content at that privilege level.

CVSS severity7.3
High
EPSS probability1.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Elevation of privilege in Microsoft .NET and bundled Visual Studio SDKs allows local users to gain elevated privileges through single-file apps. The single-file host extracts bundled files into a directory without safely preserving privilege boundaries against tampering on Unix systems. Exploitation requires an affected Linux or macOS application to run with elevated permissions and can execute attacker-controlled content at that privilege level.

The record

CVE
CVE-2021-31204
Published
May 11, 2021
Updated
Aug 3, 2024
Vendor
Microsoft
Product
Microsoft Visual Studio 2019 version 16.7
Classifications
CWE-273, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.0.0 <publication

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft Visual Studio 2019 version 16.7version=16.0.0 <publication
Microsoft · .NET Core 3.1version=3.1 <3.1.15-servicing.21214.3
Microsoft · Visual Studio for Macversion=8.0 <publication
Microsoft · Microsoft Visual Studio 2019 version 16.4version=16.0 <publication
Microsoft · Microsoft Visual Studio 2019 version 16.9version=15.0.0 <publication
Microsoft · .NET 5.0version=5.0.0 <5.0.6-servicing.21220.11

Published CVSS scores

7.3Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-273Improper Check for Dropped Privileges
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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