CVE-2024-2408: The openssl_private_decrypt function in PHP, when using PKCS1 padding (OPENSSL_PKCS1_PADDING, which is the default), is vulnerable to the Marvin Attac...

Description

The openssl_private_decrypt function in PHP, when using PKCS1 padding (OPENSSL_PKCS1_PADDING, which is the default), is vulnerable to the Marvin Attack unless it is used with an OpenSSL version that includes the changes from this pull request: https://github.com/openssl/openssl/pull/13817 (rsa_pkcs1_implicit_rejection). These changes are part of OpenSSL 3.2 and have also been backported to stable versions of various Linux distributions, as well as to the PHP builds provided for Windows since the previous release. All distributors and builders should ensure that this version is used to prevent PHP from being vulnerable. PHP Windows builds for the versions 8.1.29, 8.2.20 and 8.3.8 and above include OpenSSL patches that fix the vulnerability.

Metrics

CVSS 3.1

5.9/10

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

EPSS Probability

1.16%

63.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Php	Php	>= 8.1.0, < 8.1.29
Php	Php	>= 8.2.0, < 8.2.20
Php	Php	>= 8.3.0, < 8.3.8
Fedoraproject	Fedora	40

References

Timeline

Published: Jun 9, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-2408?

The openssl_private_decrypt function in PHP, when using PKCS1 padding (OPENSSL_PKCS1_PADDING, which is the default), is vulnerable to the Marvin Attack unless it is used with an OpenSSL version that includes the changes from this pull request: https://github.com/openssl/openssl/pull/13817 (rsa_pkcs1_implicit_rejection). These changes are part of OpenSSL 3.2 and have also been backported to stable versions of various Linux distributions, as well as to the PHP builds provided for Windows since the previous release. All distributors and builders should ensure that this version is used to prevent PHP from being vulnerable. PHP Windows builds for the versions 8.1.29, 8.2.20 and 8.3.8 and above include OpenSSL patches that fix the vulnerability.

How severe is CVE-2024-2408?

CVE-2024-2408 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 1.16% probability of exploitation in the next 30 days.

How do I fix CVE-2024-2408?

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.