CVE-2002-1831

Microsoft MSN Messenger 1.0-4.6 - Denial of Service via Hex-Encoded Spaces in Invitation-Cookie

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2002-1831. PoCs published by Beck Mr.R.

AI-analyzed exploit summary This exploit demonstrates a DoS vulnerability in MSN Messenger by sending a malformed invite request with excessive HTML-encoded space characters (%20) in the Invitation-Cookie field, causing the client to crash.

Description

Microsoft MSN Messenger Service 1.0 through 4.6 allows remote attackers to cause a denial of service (crash) via an invite request that contains hex-encoded spaces (%20) in the Invitation-Cookie field.

Exploits (1)

exploitdb WORKING POC VERIFIED
by Beck Mr.R · textdoswindows
https://www.exploit-db.com/exploits/21481

This exploit demonstrates a DoS vulnerability in MSN Messenger by sending a malformed invite request with excessive HTML-encoded space characters (%20) in the Invitation-Cookie field, causing the client to crash.

Classification
Working Poc 90%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: Microsoft MSN Messenger (versions affected by CVE-2002-1831)
No auth needed
Prerequisites: Network access to the target's MSN Messenger client
mistral-large-3 · analyzed Feb 16, 2026 Full analysis →

References (3)

Core 3
Core References
Third Party Advisory vdb-entry x_refsource_xf
http://www.iss.net/security_center/static/9161.php
Exploit vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/4827
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://online.securityfocus.com/archive/1/274086

Scores

EPSS 0.2226
EPSS Percentile 97.4%

Details

Status published
Products (8)
microsoft/msn_messenger 1.0
microsoft/msn_messenger 2.0
microsoft/msn_messenger 2.2
microsoft/msn_messenger 3.0
microsoft/msn_messenger 3.6
microsoft/msn_messenger 4.0
microsoft/msn_messenger 4.5
microsoft/msn_messenger 4.6
Published Dec 31, 2002
Tracked Since Feb 18, 2026