CVE-2021-33199

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-08-12 · updated 2026-06-17
Weakness: CWE-20

Description

In Expression Engine before 6.0.3, addonIcon in Addons/file/mod.file.php relies on the untrusted input value of input->get('file') instead of the fixed file names of icon.png and icon.svg.

Affected products

ExpressionEngine: before 6.0.3 — fixed in 6.0.3

How to fix

Upgrade to a fixed version: ExpressionEngine 6.0.3. Check the vendor advisory for mitigations.

References

https://github.com/ExpressionEngine/ExpressionEngine/compare/6.0.1...6.0.3#diff-17bcb23e5666fc2dccb79c7133e9eeb701847f67ae84fbde0a673c3fd3d109e0R508
https://github.com/ExpressionEngine/ExpressionEngine/releases/tag/6.0.3
https://github.com/ExpressionEngine/ExpressionEngine/compare/6.0.1...6.0.3#diff-17bcb23e5666fc2dccb79c7133e9eeb701847f67ae84fbde0a673c3fd3d109e0R508
https://github.com/ExpressionEngine/ExpressionEngine/releases/tag/6.0.3

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