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CVE-2021-3603

HIGHCVSS 8.1/10EPSS 2.26%

Last modified

CVE-2021-3603 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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 $patternselect parameter to validateAddress() is set to 'php' (the default, defined by PHPMailer::$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. EPSS estimates a 2.26% chance of exploitation in the next 30 days.

Description

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 $patternselect parameter to validateAddress() is set to 'php' (the default, defined by PHPMailer::$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.

Metrics

CVSS 3.1
8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
2.26%

80.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Phpmailer ProjectPhpmailer<= 6.4.1
FedoraprojectFedora33
FedoraprojectFedora34

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-3603?
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 $patternselect parameter to validateAddress() is set to 'php' (the default, defined by PHPMailer::$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.
How severe is CVE-2021-3603?
CVE-2021-3603 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 2.26% probability of exploitation in the next 30 days.
How do I fix CVE-2021-3603?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3603?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST