CVE-2019-7743

An issue was discovered in Joomla! before 3.9.3. The phar:// stream wrapper can be used for objection injection attacks because there is no protection mechanism (such as the TYPO3 PHAR stream wrapper) to prevent use of the phar:// handler for non .phar-files.

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

• http://www.securityfocus.com/bid/107050
• https://developer.joomla.org/security-centre/770-20190206-core-implement-the-typo3-phar-stream-wrapper
• http://www.securityfocus.com/bid/107050
• https://developer.joomla.org/security-centre/770-20190206-core-implement-the-typo3-phar-stream-wrapper