Cyber Resilience

CVE-2021-3603

High

Published: 17 June 2021

Published
17 June 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0078 74.1th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3603 is a high-severity Inclusion of Functionality from Untrusted Control Sphere (CWE-829) vulnerability in Fedoraproject Fedora. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 25.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

PHPMailer 6.4.1 and earlier contain a vulnerability that can result in untrusted code being called (if such code is injected into the host project's scope by other means). If the $patternselect parameter to validateAddress() is set to 'php' (the default,…

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defined by PHPMailer::$validator), and the global namespace contains a function called php, it will be called in preference to the built-in validator of the same name. Mitigated in PHPMailer 6.5.0 by denying the use of simple strings as validator function names.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

phpmailer project
phpmailer
≤ 6.4.1
fedoraproject
fedora
33, 34

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-829

Limiting P2P file sharing technology reduces inclusion of functionality or resources from untrusted external control spheres.

addresses: CWE-829

Enforcing installation policies prevents users from including functionality obtained from untrusted control spheres.

addresses: CWE-829

The inventory process requires identifying and recording the origin of all components, making inclusion of functionality from untrusted control spheres easier to detect during reviews.

addresses: CWE-829

Requiring approval and monitoring of maintenance tools prevents inclusion and execution of functionality obtained from untrusted sources.

addresses: CWE-829

Unowned portable devices represent untrusted control spheres; the prohibition prevents inclusion of functionality or data from such sources.

addresses: CWE-829

Strategy mandates assessment of third-party components and suppliers, directly reducing inclusion of functionality from untrusted control spheres.

addresses: CWE-829

Procedures can mandate supply-chain vetting and restrictions on functionality obtained from untrusted third-party or external control spheres.

addresses: CWE-829

Requires use of trusted sources and provenance tracking, tangibly limiting inclusion of functionality from untrusted control spheres.

References