Описание
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.
The RSA decryption implementation using PKCS#1 v1.5 padding in OpenSSL is vulnerable to a timing side-channel attack known as the Marvin Attack. This vulnerability arises because the execution time of the openssl_private_decrypt() function in PHP with OpenSSL varies based on whether a valid message is returned. This flaw allows an attacker to use these timing differences to decrypt captured ciphertexts or forge signatures, compromising the security of the encrypted data.
The vulnerability has been demonstrated through statistical analysis of execution times, confirming the presence of a side channel that can be leveraged in a Bleichenbacher-style attack.
Отчет
The severity of this vulnerability is considered Moderate rather than Important due to the specific conditions required for exploitation and the complexity involved in executing the attack. While the timing side-channel can potentially be used to decrypt ciphertexts or forge signatures, it necessitates a high degree of precision and a large number of measurements to discern the timing differences accurately. Additionally, the attack requires the ability to send numerous crafted ciphertexts to the decryption function and accurately measure the response times, which might not be feasible in all environments. Therefore, while the vulnerability poses a real threat, its practical exploitation is significantly constrained by these technical challenges.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | php | Out of support scope | ||
| Red Hat Enterprise Linux 7 | php | Out of support scope | ||
| Red Hat Enterprise Linux 8 | php:8.0/php | Will not fix | ||
| Red Hat Enterprise Linux 8 | php:8.2/php | Affected | ||
| Red Hat Enterprise Linux 9 | php | Will not fix | ||
| Red Hat Enterprise Linux 9 | php:8.1/php | Will not fix | ||
| Red Hat Enterprise Linux 9 | php:8.2/php | Will not fix | ||
| Red Hat Enterprise Linux 8 | openssl | Fixed | RHSA-2023:7877 | 19.12.2023 |
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Дополнительная информация
Статус:
EPSS
5.9 Medium
CVSS3
Связанные уязвимости
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.
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.
The openssl_private_decrypt function in PHP, when using PKCS1 padding ...
EPSS
5.9 Medium
CVSS3