CVE-2025-3495: Critical Security Vulnerability in Delta Electronics COMMGR Due to Insufficiently Randomized Session IDs

Overview

In this post, we delve into a recently reported critical vulnerability, identified as CVE-2025-3495, found in both versions 1 and 2 of Delta Electronics COMMGR. This vulnerability is a direct result of the application’s use of insufficiently randomized values when generating session IDs, thus making those session IDs susceptible to a brute force attack.
The software in question, Delta Electronics COMMGR, is a widely used communication manager, and any security vulnerability within it has the potential to affect a broad range of users, from individual consumers to large corporations. The high severity score of this vulnerability (9.8 out of 10) underscores its significance and the potential damage it could cause if not promptly addressed.

Vulnerability Summary

CVE ID: CVE-2025-3495
Severity: Critical (9.8 CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise, potential data leakage

Affected Products

Product | Affected Versions

Delta Electronics COMMGR | v1, v2

How the Exploit Works

The vulnerability arises from the application’s lack of sufficient randomization when generating session IDs. This makes the session IDs predictable and easily brute-forcible by an attacker. Once the attacker successfully guesses a session ID, they are essentially granted the same privileges as the user associated with that session. This allows the attacker to not only access sensitive information but also execute arbitrary code, potentially compromising the entire system.

Conceptual Example Code

The following pseudocode serves as a conceptual example of how an attacker might exploit this vulnerability:

import requests
target_url = "http://target.example.com/login"
session_id = "predictable_session_id"
headers = {
"Cookie": f"session_id={session_id}"
}
# Attempt to access the system using the predicted session ID
response = requests.get(target_url, headers=headers)
if response.status_code == 200:
print("Successful login!")
# Proceed with malicious activities
else:
print("Failed login attempt. Try another session ID.")

In this example, the attacker has predicted the session ID (`predictable_session_id`) and uses it to try to gain access to the system. If the guessed session ID is correct, the attacker can then proceed with their malicious activities.

Mitigation Guidance

To rectify this vulnerability, users are advised to apply the latest vendor-provided patch. If a patch is not yet available or cannot be implemented immediately, employing a web application firewall (WAF) or intrusion detection system (IDS) can serve as a temporary mitigation strategy. Regularly monitor your system’s logs and set up alerts for any suspicious activities or repeated failed login attempts to detect any brute force attacks.