CVE-2020-36938Public exploit

Local privilege escalation via modifiable installation binaries

Published Jan 27, 2026 · Updated Jan 27, 2026

Incorrect permissions in WinAVR 20100110 allow local users to gain elevated code execution by replacing installed DLLs or executables. The installer grants Authenticated Users Modify rights on the bin directory and inherited Modify rights on its DLL and executable files. Exploitation requires local low-privileged access and later execution of a replaced file in a higher-privileged context.

CVSS severity7.0
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect permissions in WinAVR 20100110 allow local users to gain elevated code execution by replacing installed DLLs or executables. The installer grants Authenticated Users Modify rights on the bin directory and inherited Modify rights on its DLL and executable files. Exploitation requires local low-privileged access and later execution of a replaced file in a higher-privileged context.

The record

CVE
CVE-2020-36938
Published
Jan 27, 2026
Updated
Jan 27, 2026
Vendor
WinAVR
Product
WinAVR
Classifications
CWE-732, T1574
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 27, 2026Record 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=20100110

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

WinAVR · WinAVRversion=20100110

Published CVSS scores

7.0VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8VulnCheckCVSS:3.1/AV:N/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-732Incorrect Permission Assignment for Critical Resource
T1574Hijack Execution Flow

Public exploit references

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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