CVE-2021-24307

The All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings before 4.1.0.2 enables authenticated users with aioseo_tools_settings privilege (most of the time admin) to execute arbitrary code on the underlying host. Users can restore plugins configuration by uploading a backup .ini file in the section Tool > Import/Export. However, the plugin attempts to unserialize values of the .ini file. Moreover, the plugin embeds Monolog library which can be used to craft a gadget chain and thus trigger system command execution.

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://aioseo.com/changelog/
• https://wpscan.com/vulnerability/ab2c94d2-f6c4-418b-bd14-711ed164bcf1
• https://aioseo.com/changelog/
• https://wpscan.com/vulnerability/ab2c94d2-f6c4-418b-bd14-711ed164bcf1