Deserialization of Untrusted Data in the anti CSRF module in Sitecore through 9.1 allows an authenticated attacker to execute arbitrary code by sending a serialized .NET object in an HTTP POST parameter.
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cms | Sitecore | * | 9.1 (including) |
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
References
- https://dev.sitecore.net/Downloads.aspx
- https://www.synacktiv.com/blog.html
- https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf
- https://dev.sitecore.net/Downloads.aspx
- https://www.synacktiv.com/blog.html
- https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-9875