CVE-2025-62515

Comprehensive Technical Analysis of CVE-2025-62515

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-62515

Description: The vulnerability affects the pyquokka framework, specifically in versions 0.3.1 and prior. The FlightServer class in pyquokka/flight.py uses pickle.loads() to deserialize action bodies received from Flight clients without any sanitization or validation. This occurs in the do_action() method at line 283, as well as in the cache_garbage_collect, do_put, and do_get functions. When FlightServer is configured to listen on 0.0.0.0, it allows attackers to perform arbitrary remote code execution (RCE) by sending malicious pickled payloads through the set_configs action.

CVSS Score: 9.8

Severity Evaluation: The CVSS score of 9.8 indicates a critical vulnerability. The high score is due to the potential for remote code execution, which can lead to complete system compromise. The vulnerability is easily exploitable and can be triggered remotely, making it a high-risk issue.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

1. Network-Based Attack: An attacker can send a maliciously crafted pickled payload to the FlightServer listening on 0.0.0.0. This payload can be designed to execute arbitrary code on the server.
2. Internal Network Attack: If the FlightServer is accessible within an internal network, an attacker with access to the network can exploit the vulnerability to gain control over the server.

Exploitation Methods:

1. Crafting Malicious Payloads: An attacker can create a pickled payload that includes malicious code. When this payload is deserialized by pickle.loads(), the malicious code is executed.
2. Network Scanning: Attackers can scan networks for servers running pyquokka and listening on 0.0.0.0. Once identified, they can send the malicious payload to exploit the vulnerability.

3. Affected Systems and Software Versions

Affected Software:

• pyquokka versions 0.3.1 and prior

Affected Systems:

• Any system running the vulnerable versions of pyquokka with FlightServer configured to listen on 0.0.0.0.

4. Recommended Mitigation Strategies

Immediate Mitigation:

1. Network Segmentation: Restrict access to the FlightServer by configuring it to listen on a specific IP address rather than 0.0.0.0.
2. Firewall Rules: Implement firewall rules to block unauthorized access to the FlightServer.
3. Monitoring: Increase monitoring and logging of network traffic to detect any suspicious activity.

Long-Term Mitigation:

1. Update Software: Upgrade to a patched version of pyquokka that addresses the vulnerability.
2. Input Validation: Implement proper input validation and sanitization for data received from Flight clients.
3. Use Safe Deserialization: Replace pickle.loads() with a safer deserialization method that does not execute arbitrary code.

5. Impact on Cybersecurity Landscape

Immediate Impact:

• Organizations using pyquokka are at risk of remote code execution attacks, which can lead to data breaches, system compromise, and loss of service.

Long-Term Impact:

• This vulnerability highlights the risks associated with using unsafe deserialization methods. It underscores the importance of secure coding practices and the need for robust input validation.
• The incident may prompt a review of other software components that use pickle for deserialization, leading to broader security improvements.

6. Technical Details for Security Professionals

Vulnerable Code:

# pyquokka/flight.py at line 283
def do_action(self, action_body):
    action = pickle.loads(action_body)
    # Further processing of the action

Exploitation Example:

import pickle
import socket

# Malicious payload
class Exploit:
    def __reduce__(self):
        return (os.system, ('echo "Exploited!"',))

payload = pickle.dumps(Exploit())

# Send payload to the vulnerable server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('vulnerable_server_ip', vulnerable_server_port))
s.sendall(payload)
s.close()

Mitigation Example:

import json

def do_action(self, action_body):
    action = json.loads(action_body)
    # Further processing of the action

Conclusion: The CVE-2025-62515 vulnerability in pyquokka is a critical issue that requires immediate attention. Organizations should prioritize updating to a patched version and implementing robust input validation to mitigate the risk of remote code execution. This incident serves as a reminder of the importance of secure coding practices and the need for continuous monitoring and updating of software components.