CVE-2016-1902: Symfony Cryptographic Vulnerability
Summary
CVE-2016-1902: Symfony Cryptographic Vulnerability. Affects symfony/security-core across 2 version ranges.
>= 2.4.0, < 2.6.13
>= 2.7.0, < 2.7.9
Fixed in 2.6.13 or 2.7.9, depending on the release line you run. How to fix ↓
Also tracked for
- symfony · Debian:11
The same CVE-2016-1902 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
Symfony is a popular PHP framework used for developing web applications. It provides a set of reusable components and tools that simplify the development process. The SecureRandom class in Symfony is responsible for generating random numbers used for cryptographic operations. However, versions before 2.3.37, 2.6.x before 2.6.13, and 2.7.x before 2.7.9 have a vulnerability in the nextBytes function. When used with PHP 5.x without the paragonie/random_compat library and the openssl_random_pseudo_bytes function fails, the random numbers generated are not secure. This vulnerability can be exploited by attackers to bypass cryptographic protection mechanisms.
Vulnerability Detail
The vulnerability in Symfony's SecureRandom class allows attackers to defeat cryptographic protection mechanisms. When the nextBytes function is used with PHP 5.x without the paragonie/random_compat library and the openssl_random_pseudo_bytes function fails, the random numbers generated are not secure. This makes it easier for attackers to compromise the cryptographic operations performed by the application. The specific vectors through which this vulnerability can be exploited are unspecified.
How To Fix
Fixed versions by release line
The minimum fixed version depends on the release line you run.
-
>= 2.4.0, < 2.6.132.6.13composer require symfony/security-core:2.6.13 -
>= 2.7.0, < 2.7.92.7.9composer require symfony/security-core:2.7.9
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Workaround
If updating Symfony is not immediately feasible, a workaround is to manually install the paragonie/random_compat library and ensure that the openssl_random_pseudo_bytes function is functioning correctly. This will provide secure random number generation even with PHP 5.x. Here is an example of how to install the library using Composer:
composer require paragonie/random_compat
Once the library is installed, ensure that the openssl_random_pseudo_bytes function is working as expected.
Conclusion
The Symfony Cryptographic Vulnerability (CVE-2016-1902) affects versions of Symfony before 2.3.37, 2.6.x before 2.6.13, and 2.7.x before 2.7.9. It allows attackers to defeat cryptographic protection mechanisms by exploiting the insecure random number generation. To fix this vulnerability, it is recommended to update Symfony to the fixed versions and ensure the use of PHP 7.x or higher. For further support on vulnerability remediation, contact DevNack.com.
See every vulnerability recorded for symfony/security-core →
FAQ
Symfony is a PHP framework used for developing web applications. It provides a set of reusable components and tools that simplify the development process.
The SecureRandom class in Symfony is responsible for generating random numbers used for cryptographic operations.
Versions before 2.3.37, 2.6.x before 2.6.13, and 2.7.x before 2.7.9 are affected by this vulnerability.
The specific vectors through which this vulnerability can be exploited are unspecified.
The recommended fix is to update Symfony to version 2.3.37, 2.6.13, or 2.7.9, depending on the version being used. It is also recommended to use PHP 7.x or higher.
References
Related vulnerabilities
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