FireEye EDR (Endpoint Detection and Response) agent provides security experts with real-time visibility, threat detection, and response capabilities to defend against cyber threats. However, a recent discovery of a persistent denial of service vulnerability (CVE-2025-0618) allows a malicious third party to cause havoc on the FireEye EDR agent by virtually enhancing its tamper protection events. In this long read, we will take a closer look at this vulnerability, as well as the underlying exploit details. The vulnerability centers around sending a tamper protection event to the HX service in a way that triggers an exception rendering tamper protection system dysfunctional even after a reboot of HX.

The following code snippet demonstrates how the vulnerability can be triggered

import socket

# Replace with your target IP and port
target_ip = "192.168.1.10"
target_port = 9999

# Creates a specially-crafted tamper protection event
def create_tamper_event():
    event = ""
    # Add your tamper event details here
    return event

# Sends the tamper protection event to the target
def send_tamper_event(event):
    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((target_ip, target_port))
        sock.sendall(event.encode("utf-8"))
        sock.close()
    except Exception as e:
        print(f"Error occurred: {str(e)}")

if __name__ == "__main__":
    tamper_event = create_tamper_event()
    send_tamper_event(tamper_event)

Exploit Details

A tamper protection event typically monitors unauthorized access or modification attempts made to an endpoint or system. In the context of the FireEye EDR agent, the vulnerability CVE-2025-0618 targets the HX service, which is responsible for processing these tamper protection events. By carefully crafting the tamper protection event and sending it to the HX service, a remote attacker can force the service to produce an exception due to the malformed tamper protection event provided. This exception subsequently halts the processing of other tamper protection events.

As a particularly devastating implication, this vulnerability not only affects a single tamper protection event but also persists reboot attempts of the HX service. This effectively locks out the tamper protection system of FireEye EDR agent and creates a denial of service condition that impedes detection and response capabilities of this security solution.

Potential Impact

Organizations affected by this vulnerability may experience a substantial reduction in their ability to detect, respond, and prevent cyber incidents involving FireEye EDR agents. Attackers aware of this vulnerability and capable of exploiting it can cause a persistent denial of service state that reduces the overall effectiveness of the EDR agent. This can lead to significant business impact, and in the worst-case scenario, the compromise of sensitive data or critical systems.

Mitigation Steps

Fortunately, FireEye has released a patch to address this vulnerability that organizations should apply as soon as possible. We also recommend implementing additional security configurations, such as network segmentation and continuous monitoring, to minimize the potential impact of future similar attacks.

In conclusion, the persistent denial of service vulnerability (CVE-2025-0618) present in FireEye EDR agent poses a notable threat to organizations reliant on these solutions to maintain their security posture. By understanding how the exploit works and taking the necessary mitigation measures, organizations can work towards reinstating their security and ensuring the ongoing detection and response of cyber threats.

Timeline

Published on: 04/23/2025 07:15:42 UTC
Last modified on: 04/23/2025 14:08:13 UTC