CVE-2020-35932

Insecure Deserialization in the Newsletter plugin before 6.8.2 for WordPress allows authenticated remote attackers with minimal privileges (such as subscribers) to use the tpnc_render AJAX action to inject arbitrary PHP objects via the options[inline_edits] parameter. NOTE: exploitability depends on PHP objects that might be present with certain other plugins or themes.

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://www.wordfence.com/blog/2020/08/newsletter-plugin-vulnerabilities-affect-over-300000-sites/
• https://www.wordfence.com/blog/2020/08/newsletter-plugin-vulnerabilities-affect-over-300000-sites/