CVE-2025-15117 identifies a deserialization vulnerability in the Dromara Sa-Token library, specifically in the ObjectInputStream.readObject method within the SaJdkSerializer.java file. Sa-Token is a Java-based authentication and authorization framework widely used in various applications for session and token management. The vulnerability arises from unsafe deserialization practices, where untrusted serialized data can be manipulated and passed to the readObject method, potentially allowing attackers to execute arbitrary code or cause denial of service if exploited. However, the attack complexity is high, meaning that exploitation requires significant expertise and specific conditions. The vulnerability can be triggered remotely without user interaction but requires low privileges, indicating that an attacker with limited access could attempt exploitation. The CVSS 4.0 base score is 2.3, reflecting a low severity level due to limited impact on confidentiality, integrity, and availability, and the presence of high attack complexity. The vendor was contacted but did not respond, and no patches or mitigations have been officially released yet. No known exploits have been observed in the wild, suggesting limited current threat but potential future risk. The vulnerability affects all versions of Sa-Token up to 1.44.0, which encompasses the entire released range of the product. This vulnerability is a classic example of insecure deserialization, a common issue in Java applications that can lead to serious security breaches if exploited successfully.

For European organizations, the impact of CVE-2025-15117 is currently low but should not be ignored. Organizations relying on Sa-Token for authentication or session management could face risks if attackers manage to exploit the deserialization flaw, potentially leading to unauthorized code execution or denial of service. Although the current exploitability is difficult and no known exploits exist, the remote attack vector means that exposed services accepting serialized input could be targeted. This could affect web applications, microservices, or APIs using Sa-Token, especially in sectors with high security requirements such as finance, healthcare, and government. The lack of vendor response and patches increases the risk window. Additionally, if attackers develop reliable exploits, the impact could escalate rapidly. European organizations with compliance obligations under GDPR must consider the risk of data breaches or service disruptions resulting from exploitation. The vulnerability's low CVSS score reflects limited immediate risk but does not preclude future exploitation or chaining with other vulnerabilities to increase impact.

1. Immediately audit all applications using Sa-Token to identify usage of the vulnerable versions (up to 1.44.0). 2. Avoid accepting or processing untrusted serialized data; implement strict input validation and sanitization on all serialized inputs. 3. Where possible, disable Java deserialization or replace ObjectInputStream.readObject with safer serialization frameworks that enforce type whitelisting or use JSON/XML serialization. 4. Employ runtime application self-protection (RASP) or Web Application Firewalls (WAF) to detect and block suspicious serialized payloads. 5. Monitor application logs for anomalies related to deserialization errors or unexpected object instantiations. 6. Isolate services using Sa-Token in segmented network zones to limit lateral movement if exploited. 7. Engage with the vendor or community for updates or patches and apply them promptly once available. 8. Conduct security code reviews focusing on serialization/deserialization logic to identify and remediate unsafe patterns. 9. Educate developers on secure deserialization best practices and the risks associated with Java serialization. 10. Prepare incident response plans for potential exploitation scenarios involving deserialization attacks.