CVE-2019-12799

In createInstanceFromNamedArguments in Shopware through 5.6.x, a crafted web request can trigger a PHP object instantiation vulnerability, which can result in an arbitrary deserialization if the right class is instantiated. An attacker can leverage this deserialization to achieve remote code execution. NOTE: this issue is a bypass for a CVE-2017-18357 whitelist patch.

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://github.com/rapid7/metasploit-framework/pull/11828
• https://github.com/rapid7/metasploit-framework/pull/11828