CVE-2011-4040

NJStar Communicator MiniSmtp 3.0.11818 - Remote Code Execution via Crafted Packet

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 3 public exploits for CVE-2011-4040. PoCs published by Dillon Beresford, Zune, including Metasploit module exploits/windows/smtp/njstar_smtp_bof.

AI-analyzed exploit summary This is a Metasploit module exploiting a stack overflow vulnerability in NJStar Communicator 3.00 MiniSMTP server. It uses an egghunter technique to bypass stack space constraints and achieves remote code execution on various Windows versions.

Description

Buffer overflow in MiniSmtp 3.0.11818 in NJStar Communicator allows remote attackers to execute arbitrary code via a crafted packet.

Exploits (3)

exploitdb WORKING POC VERIFIED
by Dillon Beresford · rubyremotewindows
https://www.exploit-db.com/exploits/18057

This is a Metasploit module exploiting a stack overflow vulnerability in NJStar Communicator 3.00 MiniSMTP server. It uses an egghunter technique to bypass stack space constraints and achieves remote code execution on various Windows versions.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: NJStar Communicator 3.00 and prior (MiniSMTP Server)
No auth needed
Prerequisites: Network access to the MiniSMTP server (port 25)
devstral-2 · analyzed Feb 16, 2026 Full analysis →
exploitdb WORKING POC
by Zune · pythondoswindows
https://www.exploit-db.com/exploits/18196

This exploit targets a buffer overflow vulnerability in NJStar Communicator 3.0 MiniSmtp service, bypassing ASLR on Windows 7. It sends multiple crafted packets to trigger the overflow and execute shellcode.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: NJStar Communicator 3.0 (Build 11818 and previous)
No auth needed
Prerequisites: Network access to the target's SMTP port (25) · Target running NJStar Communicator 3.0 with vulnerable MiniSmtp service
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit WORKING POC NORMAL
by Dillon Beresford · rubypocwin
https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/smtp/njstar_smtp_bof.rb

This Metasploit module exploits a stack buffer overflow in NJStar Communicator 3.00 MiniSMTP server via a maliciously crafted SMTP command. It uses an egghunter to bypass space constraints and achieves remote code execution on vulnerable Windows systems.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: NJStar Communicator 3.00 MiniSMTP server
No auth needed
Prerequisites: Network access to the MiniSMTP server on port 25 · Vulnerable version of NJStar Communicator
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (1)

Core 1
Core References
US Government Resource third-party-advisory x_refsource_cert-vn
http://www.kb.cert.org/vuls/id/819630

Scores

EPSS 0.6568
EPSS Percentile 99.2%

Details

CWE
CWE-119
Status published
Products (1)
njstar/njstar_communicator 3.0.11818
Published Nov 21, 2011
Tracked Since Feb 18, 2026