CVE-2011-10020

HIGH

Kaillera Server < 0.86 - Unauthenticated Denial of Service via Malformed UDP Packet

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2011-10020. PoCs published by Sil3nt_Dre4m, including Metasploit module auxiliary/dos/windows/games/kaillera.

AI-analyzed exploit summary This Perl script exploits multiple buffer overflow vulnerabilities in various Kaillera clients by acting as a malicious Kaillera server. It targets specific emulators and Kaillera client versions, delivering a Metasploit-generated calc.exe shellcode payload.

Description

Kaillera Server version 0.86 is vulnerable to a denial-of-service condition triggered by sending a malformed UDP packet after the initial handshake. Once a client sends a valid HELLO0.83 packet and receives a response, any subsequent malformed packet causes the server to crash and become unresponsive. This flaw stems from improper input validation in the server’s UDP packet handler, allowing unauthenticated remote attackers to disrupt service availability.

Exploits (2)

exploitdb WORKING POC
by Sil3nt_Dre4m · perlremotewindows
https://www.exploit-db.com/exploits/17460

This Perl script exploits multiple buffer overflow vulnerabilities in various Kaillera clients by acting as a malicious Kaillera server. It targets specific emulators and Kaillera client versions, delivering a Metasploit-generated calc.exe shellcode payload.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Kaillera clients (0.9, Supraclient 0.85.2, Open Kaillera n02v0r6) with specific emulators (Mame32k, Snes9k, Mupen64k, Mame32++)
No auth needed
Prerequisites: Network access to target · Target must connect to the malicious server · Specific vulnerable Kaillera client and emulator versions
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit WORKING POC
by Sil3nt_Dre4m · rubypoc
https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/dos/windows/games/kaillera.rb

This Metasploit module exploits a denial-of-service vulnerability in Kaillera 0.86 by sending a malformed packet after the initial 'HELLO' packet, causing the server to crash. It verifies the crash by attempting to reconnect.

Classification
Working Poc 100%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: Kaillera 0.86
No auth needed
Prerequisites: Network access to the target server on UDP port 27888
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Scores

CVSS v4 8.7
EPSS 0.5144
EPSS Percentile 98.0%
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-20
Status published
Products (1)
Kaillera Project/Server < 0.86
Published Aug 20, 2025
Tracked Since Feb 18, 2026