CVE-2025-58163

FreeScout is a free help desk and shared inbox built with PHPs Laravel framework. Versions 1.8.185 and earlier contain a deserialization of untrusted data vulnerability that allows authenticated attackers with knowledge of the applications APP_KEY to achieve remote code execution. The vulnerability is exploited via endpoint, e.g.: /help/{mailbox_id}/auth/{customer_id}/{hash}/{timestamp} where the customer_id and timestamp parameters are processed through the decrypt function in app/Helper.php without proper validation. The code decrypts using Laravels built-in encryption functions, which subsequently deserialize the decrypted payload without sanitization, allowing attackers to craft malicious serialized PHP objects using classes to trigger arbitrary command execution. This is fixed in version 1.8.186.

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/freescout-help-desk/freescout/commit/e2de65f3f32f825b4ec5558643ed81438c9a6bc6
• https://github.com/freescout-help-desk/freescout/releases/tag/1.8.186
• https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-j94w-q9gj-c37g