CVE-2021-41526

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.

Published: 2023-03-29 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-41526 is rated Low Risk (38/100): CVSS High severity, with low exploitation likelihood (EPSS 0.07%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-41526

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-17 0.04% 0.07% +0.03%
2 2023-03-30 0.04%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41526

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.9 [email protected]

Weakness enumeration for CVE-2021-41526

Affected software / configurations for CVE-2021-41526

Vendor Product Version Raw CPE
flexera revenera_installshield < 2021 cpe:2.3:a:flexera:revenera_installshield:*:*:*:*:*:windows:*:*
flexera revenera_installshield 2021 cpe:2.3:a:flexera:revenera_installshield:2021:-:*:*:*:windows:*:*
flexera revenera_installshield 2021 cpe:2.3:a:flexera:revenera_installshield:2021:r1:*:*:*:windows:*:*

References for CVE-2021-41526

cvelogic Threat Intelligence