What’s Vulnerable › Vulnerabilities

CVE-2021-41526

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-03-29 · updated 2026-06-17

Description

A vulnerability has been reported in the windows installer (MSI) built with InstallScript custom action. This vulnerability may allow privilege escalation when invoked ‘repair’ of the MSI which has an InstallScript custom action.

Affected products

• Flexera Revenera Installshield: before 2021; 2021, 2021-r1 — fixed in 2021

How to fix

Upgrade to a fixed version: Flexera Revenera Installshield 2021. Check the vendor advisory for mitigations.

References

• http://seclists.org/fulldisclosure/2024/Apr/24
• https://community.flexera.com/t5/InstallShield-Knowledge-Base/CVE-2021-41526-Privilege-escalation-vulnerability-during-MSI/ta-p/218137/jump-to/first-unread-message
• https://github.com/mandiant/Vulnerability-Disclosures/blob/master/MNDT-2021-0011/MNDT-2021-0011.md
• http://seclists.org/fulldisclosure/2024/Apr/24
• https://community.flexera.com/t5/InstallShield-Knowledge-Base/CVE-2021-41526-Privilege-escalation-vulnerability-during-MSI/ta-p/218137/jump-to/first-unread-message
• https://github.com/mandiant/Vulnerability-Disclosures/blob/master/MNDT-2021-0011/MNDT-2021-0011.md

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