{"id":"CVE-2021-25299","title":"Nagios XI version xi-5.7.5 is affected by cross-site scripting (XSS)","summary":"Nagios XI version xi-5.7.5 is affected by cross-site scripting (XSS). The vulnerability exists in the file /usr/local/nagiosxi/html/admin/sshterm.php due to improper sanitization of user-controlled input. A maliciously crafted URL, when …","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"vendor":"nagios","product":"nagios_xi","affected":["nagios_xi = 5.7.5"],"published":"2021-02-15","updated":"2026-07-05","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-25299","references":[{"url":"http://packetstormsecurity.com/files/161561/Nagios-XI-5.7.5-Remote-Code-Execution.html","label":"cve@mitre.org"},{"url":"https://assets.nagios.com/downloads/nagiosxi/versions.php","label":"cve@mitre.org"},{"url":"https://github.com/fs0c-sh/nagios-xi-5.7.5-bugs/blob/main/README.md","label":"cve@mitre.org"},{"url":"http://nagios.com","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://packetstormsecurity.com/files/161561/Nagios-XI-5.7.5-Remote-Code-Execution.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://assets.nagios.com/downloads/nagiosxi/versions.php","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/fs0c-sh/nagios-xi-5.7.5-bugs/blob/main/README.md","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","exploit-available"],"epss":0.9776,"epssPercentile":0.99903,"ingestedAt":"2026-07-05T00:59:25.820Z","exploits":{"nuclei":["CVE-2021-25299"],"checkedAt":"2026-09-21T15:24:10.796Z"},"exploitAvailable":true,"slug":"CVE-2021-25299","body":"## Overview\n\nNagios XI version xi-5.7.5 is affected by cross-site scripting (XSS). The vulnerability exists in the file /usr/local/nagiosxi/html/admin/sshterm.php due to improper sanitization of user-controlled input. A maliciously crafted URL, when clicked by an admin user, can be used to steal his/her session cookies or it can be chained with the previous bugs to get one-click remote command execution (RCE) on the Nagios XI server.\n\n## Affected\n\n- `nagios_xi = 5.7.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":65,"depthScoreParts":{"impact":33.6,"likelihood":19.6,"exploitation":12,"ransomware":0},"changes":[{"seq":4510,"id":"CVE-2021-25299","ts":1788887186156,"field":"exploit_available","old":"false","new":"true"},{"seq":3393,"id":"CVE-2021-25299","ts":1788886303873,"field":"exploit_available","old":"true","new":"false"},{"seq":2248,"id":"CVE-2021-25299","ts":1788882973493,"field":"exploit_available","old":"false","new":"true"},{"seq":1277,"id":"CVE-2021-25299","ts":1788882385159,"field":"exploit_available","old":"true","new":"false"},{"seq":391,"id":"CVE-2021-25299","ts":1788881820514,"field":"exploit_available","old":"false","new":"true"}]}