{"id":"UBUNTU-CVE-2021-21708","details":"In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.","modified":"2026-04-22T14:34:57.495391Z","published":"2021-12-31T00:00:00Z","related":["USN-5303-1"],"upstream":["CVE-2021-21708"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-21708"},{"type":"REPORT","url":"https://nakedsecurity.sophos.com/2022/02/18/irony-alert-php-fixes-security-flaw-in-input-validation-code/"},{"type":"REPORT","url":"https://www.php.net/ChangeLog-8.php#PHP_8_1"},{"type":"REPORT","url":"https://www.php.net/ChangeLog-7.php#PHP_7_4"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5303-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-21708"}],"affected":[{"package":{"name":"php7.4","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/php7.4@7.4.3-4ubuntu2.9?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.4.3-4ubuntu2.9"}]}],"versions":["7.4.3-4build1","7.4.3-4build2","7.4.3-4ubuntu1","7.4.3-4ubuntu1.1","7.4.3-4ubuntu2.2","7.4.3-4ubuntu2.4","7.4.3-4ubuntu2.5","7.4.3-4ubuntu2.6","7.4.3-4ubuntu2.7","7.4.3-4ubuntu2.8"],"ecosystem_specific":{"availability":"No 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