CVE-2025-25374

Executive Summary

CVE-2025-25374 is a high-severity denial-of-service (DoS) vulnerability in NASA's Core Flight System (cFS) Aquila. The flaw allows an attacker to place the onboard software into a state that prevents the launch of any external application, effectively causing a platform-level denial of service. This vulnerability is particularly critical for space missions and embedded systems relying on cFS, as it can lead to complete loss of spacecraft control or mission abort. No public exploit code or patch details are currently available, and the EPSS score is 0.0%, indicating low exploitation activity in the wild.

Supply Chain & Package Security

This vulnerability affects NASA's cFS Aquila, which is a core component of the flight software ecosystem. While not a typical package manager dependency (e.g., NPM, PyPI), the cFS is distributed as source code and integrated into mission-specific builds. Organizations using cFS should verify their version and apply any available patches from NASA's official repositories.

CVSS Breakdown & Threat Level

• CVSS Score: 7.5 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
• Attack Vector: Network (AV:N) – The vulnerability can be triggered remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – The vulnerable component remains isolated.
• Confidentiality Impact: None (C:N) – No data exposure.
• Integrity Impact: None (I:N) – No data modification.
• Availability Impact: High (A:H) – Complete denial of service.

Threat Level: High. The vulnerability is remotely exploitable with low complexity and no authentication, making it a prime target for adversaries seeking to disrupt critical space infrastructure.

Deep Dive & Mechanics

The vulnerability resides in the Aquila version of NASA's Core Flight System (cFS). cFS is a reusable software framework for spaceflight missions, providing services like task management, communication, and file handling. The flaw specifically affects the application launch mechanism, likely within the Executive Services (ES) component.

Root Cause: The vulnerability is a CWE-248: Uncaught Exception. When a specific sequence of commands or malformed data is sent to the cFS, it triggers an unhandled exception in the application launch logic. This exception corrupts the internal state of the ES, preventing any subsequent external applications from being started. The system remains operational but is effectively bricked for new tasks.

Attack Vector: An attacker can send specially crafted packets over the network (e.g., via the cFS's command and telemetry interface) to exploit this flaw. The attack does not require authentication, as cFS often operates in trusted network environments without strict access controls.

Impact: Once triggered, the system enters a deadlock state where no new applications can be launched. This can lead to mission failure, loss of telemetry, and inability to execute critical commands. The only recovery method is a full system reset, which may not be possible in remote spacecraft.

Vulnerable vs. Patched Code

Since no patch is publicly available, the following is a hypothetical analysis based on the vulnerability description.

Vulnerable Code (Conceptual):

// In ES_AppStart.c
int32 ES_StartApp(char *appName) {
    // ... validation and setup ...
    int32 status = OS_TaskCreate(&taskID, appName, ...);
    if (status != OS_SUCCESS) {
        // Missing error handling - no cleanup or state reset
        return status; // Returns error but leaves system in inconsistent state
    }
    // ... rest of startup ...
}

Patched Code (Hypothetical):

// In ES_AppStart.c
int32 ES_StartApp(char *appName) {
    // ... validation and setup ...
    int32 status = OS_TaskCreate(&taskID, appName, ...);
    if (status != OS_SUCCESS) {
        // Proper error handling - reset state and clean up
        ES_ResetAppLaunchState();
        return status;
    }
    // ... rest of startup ...
}

The patch would involve adding robust exception handling and state cleanup in the application launch routine to prevent the system from entering an unrecoverable state.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Access to the cFS network interface (e.g., UDP port 1234 for command packets).
• Knowledge of the cFS command packet format (CCSDS or custom).

Exploit Concept:

1. Identify the cFS command port (default often UDP 1234).
2. Craft a malformed command packet that triggers the uncaught exception in the application launch service.
3. Send the packet repeatedly to ensure the system enters the deadlock state.

Example Python Script (Conceptual):

import socket
import struct

target_ip = "192.168.1.100"
target_port = 1234

# Craft a malformed command packet (hypothetical)
# This packet would cause an unhandled exception in ES_StartApp
packet = b"\x01\x02\x03\x04"  # Placeholder for actual exploit data

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(packet, (target_ip, target_port))
print("Exploit sent. System should now be in DoS state.")

Note: No public exploit code exists. This is a conceptual demonstration.

Blue Team (Defensive)

Detection:

• Monitor for anomalous command packets that deviate from expected cFS protocol.
• Look for repeated failed application launch attempts in logs.
• Use network intrusion detection systems (NIDS) to flag malformed packets.

Mitigation:

• Isolate cFS network interfaces from untrusted networks.
• Implement authentication for command packets (e.g., HMAC).
• Apply input validation and error handling in the application launch service.

Lab Setup:

1. Deploy a cFS Aquila instance in a virtualized environment (e.g., QEMU or Docker).
2. Configure network access to the command port.
3. Use Wireshark to capture traffic and analyze exploit attempts.
4. Test detection rules (see Detection Engineering).

Indicators of Compromise (IOCs)

• Network:
  • UDP packets to port 1234 (or configured command port) with malformed payloads.
  • Repeated failed application launch events in cFS logs.
• System:
  • cFS console output showing "ES_StartApp failed" errors without subsequent recovery.
  • Inability to start new applications after a specific network event.
• Logs:
  • /cf/evs_log.txt entries with error codes related to application launch failures.

Detection Engineering

YARA Rule

rule CVE_2025_25374_cFS_Aquila_DoS {
    meta:
        description = "Detects malformed command packets targeting NASA cFS Aquila DoS vulnerability"
        author = "Valters IT"
        date = "2025-03-01"
        reference = "CVE-2025-25374"
    strings:
        $cmd_header = { 01 02 03 04 }  // Placeholder for actual exploit signature
        $error_msg = "ES_StartApp failed" nocase
    condition:
        $cmd_header or $error_msg
}

Sigma Rule

title: CVE-2025-25374 - NASA cFS Aquila Denial of Service
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects network traffic targeting the cFS command port with malformed packets
author: Valters IT
date: 2025-03-01
logsource:
    category: network
    product: suricata
detection:
    selection:
        dest_port: 1234
        payload|contains: "01020304"  // Placeholder for exploit pattern
    condition: selection
falsepositives:
    - Legitimate cFS command traffic
level: high

Suricata Rule

alert udp any any -> any 1234 (msg:"CVE-2025-25374 - NASA cFS Aquila DoS Attempt"; content:"|01 02 03 04|"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Isolate cFS systems on dedicated, air-gapped networks.
2. Access Control: Implement strict firewall rules to limit access to the cFS command port.
3. Monitoring: Deploy the provided detection rules to identify exploit attempts.

Long-Term Fix:

• Await an official patch from NASA. Monitor the cFS GitHub repository (https://github.com/nasa/cFS) for updates.
• Apply input validation and error handling in the application launch service.
• Consider using a Web Application Firewall (WAF) or protocol validator for cFS traffic.

Workaround:

• If patching is not possible, disable the application launch service if not required, or implement a watchdog timer that resets the system upon detecting a deadlock.

Valters IT
Securing Space Systems, One CVE at a Time.