CVE-2024-10044: SSRF Vulnerability in lm-sys/fastchat API

 CVE-2024-10044: Critical SSRF Vulnerability in 

lm-sys/fastchat API

CVE-2024-10044 is a critical Server-Side Request Forgery (SSRF) vulnerability identified in the POST /worker_generate_stream API endpoint of the Controller API Server within the lm-sys/fastchat project. This vulnerability was introduced as of commit e208d5677c6837d590b81cb03847c0b9de100765. It has been assigned a Base Score of 9.3, categorizing it as a critical security risk due to its potential for exploitation by attackers. (dec, 30 2024)

Nature of the Vulnerability

The SSRF vulnerability allows an attacker to manipulate the server into making unauthorized requests to internal or external resources. Specifically, by leveraging this flaw, attackers can exploit the victim's Controller API server credentials to perform unauthorized web actions or access restricted web resources. This is particularly concerning when combined with the POST /register_worker endpoint, which may further escalate the attack's impact.

Technical Details

In SSRF attacks, the attacker typically submits a crafted request that leads the server to make requests to unintended locations. In this case, the vulnerability allows attackers to specify arbitrary URLs that the server will access. This can enable them to bypass security measures and interact with internal services that are not otherwise accessible from outside the network.

Example Scenario

Consider a scenario where an organization uses lm-sys/fastchat for managing chat services. The Controller API Server is responsible for handling various requests, including worker registration and stream generation.

1. Initial Access: An attacker gains access to the application, perhaps through phishing or exploiting another vulnerability.
2. Exploitation: The attacker crafts a POST request to the /worker_generate_stream endpoint, including a malicious URL in the request body. For example:

   text
   POST /worker_generate_stream HTTP/1.1
   Host: victim-controller-api.com
   Content-Type: application/json
   
   {
       "url": "http://internal-service.local/admin"
   }
   

3. Server Response: The vulnerable server processes this request and makes a backend call to http://internal-service.local/admin, which is an internal administrative interface that should not be publicly accessible.
4. Unauthorized Access: If successful, the attacker can now interact with sensitive internal services, potentially leading to data exfiltration or further exploitation of internal systems.

Implications of CVE-2024-10044

The implications of this vulnerability are severe:

• Data Exposure: Attackers could access sensitive information stored within internal services.
• Privilege Escalation: By gaining access to administrative interfaces, attackers might escalate their privileges within the system.
• Wider Network Compromise: The ability to reach internal services can lead to further exploitation of other vulnerabilities within the network.

Mitigation Strategies

To mitigate risks associated with CVE-2024-10044, organizations should consider implementing the following strategies:

• Patch Management: Ensure that all instances of lm-sys/fastchat are updated to versions that address this vulnerability.
• Network Segmentation: Limit access to internal services from external networks and employ strict firewall rules.
• Input Validation: Implement robust input validation mechanisms in API endpoints to prevent unauthorized URL submissions.
• Monitoring and Logging: Enhance monitoring of API usage patterns and log requests for potential indicators of exploitation attempts.

Conclusion

CVE-2024-10044 represents a significant security threat due to its critical nature and potential for exploitation through SSRF attacks. Organizations utilizing lm-sys/fastchat must prioritize addressing this vulnerability through timely updates and enhanced security practices to safeguard their systems against potential breaches.