{"id":"CVE-2011-10020","aliases":["EUVD-2011-5257","GHSA-r56f-c7p9-h5jg"],"status":"published","title":"Kaillera 0.86 Server DoS via Malformed UDP Packet","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.","severity":{"version":"4.0","score":8.7,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01395,"percentile":0.72628,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2025-08-20T15:35:41Z","modified":"2026-06-16T23:28:29Z","exploits":[{"source":"metasploit","id":"auxiliary/dos/windows/games/kaillera","title":"Kaillera 0.86 Server Denial of Service","type":"auxiliary","date":"2011-07-02","verified":true,"url":"https://www.rapid7.com/db/modules/auxiliary/dos/windows/games/kaillera"}],"products":[{"vendor":"devolutions","product":"server"},{"vendor":"kaillera project","product":"server"}],"references":[{"url":"https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/auxiliary/dos/windows/games/kaillera.rb","tags":["exploit"]},{"url":"https://www.exploit-db.com/exploits/17460","tags":["exploit"]},{"url":"http://kaillera.com/","tags":["product"]},{"url":"https://www.vulncheck.com/advisories/kaillera-server-dos-via-malformed-udp-packet","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2011-10020"},{"url":"http://kaillera.com"},{"url":"https://github.com/advisories/GHSA-r56f-c7p9-h5jg"}],"sources":{"cve":[{"id":"CVE-2011-10020","title":"Kaillera 0.86 Server DoS via Malformed UDP Packet","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.","status":"published","published":"2025-08-20T15:35:41.803Z","modified":"2026-05-15T11:13:42.877Z","cvss":[{"version":"4.0","score":8.7,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:35:36.252742Z"}],"euvd":[{"id":"EUVD-2011-5257","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.","status":"published","published":"2025-08-20T15:35:41Z","modified":"2026-05-15T11:13:42Z","cvss":[{"version":"4.0","score":8.7,"vector":"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","level":"high"}],"updated_at":"2026-11-02T19:04:29.443212Z"}],"ghsa":[{"id":"GHSA-r56f-c7p9-h5jg","title":"Kaillera Server version 0.86 is vulnerable to a denial-of-service condition triggered by sending...","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.","status":"published","published":"2025-08-20T18:30:21Z","modified":"2025-08-20T18:30:22Z","cvss":[{"version":"4.0","score":8.7,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:03:21.511205Z"}],"nvd":[{"id":"CVE-2011-10020","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.","status":"published","published":"2025-08-20T16:15:34.327Z","modified":"2026-06-16T23:28:29.007Z","cvss":[{"version":"4.0","score":8.7,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:02:12.945371Z"}]}}