{"id":"UBUNTU-CVE-2021-40524","details":"In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)","modified":"2026-05-20T16:05:09.542356589Z","published":"2021-09-05T19:15:00Z","upstream":["CVE-2021-40524"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-40524"},{"type":"REPORT","url":"https://github.com/jedisct1/pure-ftpd/pull/158"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-40524"}],"affected":[{"package":{"name":"pure-ftpd","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/pure-ftpd?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.36-3.2","1.0.36-3.2build1","1.0.36-3.2+deb8u1build0.16.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"pure-ftpd","binary_version":"1.0.36-3.2+deb8u1build0.16.04.1"},{"binary_version":"1.0.36-3.2+deb8u1build0.16.04.1","binary_name":"pure-ftpd-common"},{"binary_name":"pure-ftpd-ldap","binary_version":"1.0.36-3.2+deb8u1build0.16.04.1"},{"binary_version":"1.0.36-3.2+deb8u1build0.16.04.1","binary_name":"pure-ftpd-mysql"},{"binary_name":"pure-ftpd-postgresql","binary_version":"1.0.36-3.2+deb8u1build0.16.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40524.json"}},{"package":{"name":"pure-ftpd","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/pure-ftpd?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.46-1","1.0.46-1build1","1.0.46-1ubuntu18.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0.46-1ubuntu18.04.1","binary_name":"pure-ftpd"},{"binary_name":"pure-ftpd-common","binary_version":"1.0.46-1ubuntu18.04.1"},{"binary_name":"pure-ftpd-ldap","binary_version":"1.0.46-1ubuntu18.04.1"},{"binary_name":"pure-ftpd-mysql","binary_version":"1.0.46-1ubuntu18.04.1"},{"binary_name":"pure-ftpd-postgresql","binary_version":"1.0.46-1ubuntu18.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40524.json"}},{"package":{"name":"pure-ftpd","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/pure-ftpd?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.47-3build1","1.0.49-1","1.0.49-2","1.0.49-3","1.0.49-4","1.0.49-4ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0.49-4ubuntu0.1","binary_name":"pure-ftpd"},{"binary_version":"1.0.49-4ubuntu0.1","binary_name":"pure-ftpd-common"},{"binary_name":"pure-ftpd-ldap","binary_version":"1.0.49-4ubuntu0.1"},{"binary_name":"pure-ftpd-mysql","binary_version":"1.0.49-4ubuntu0.1"},{"binary_name":"pure-ftpd-postgresql","binary_version":"1.0.49-4ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40524.json"}},{"package":{"name":"pure-ftpd","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/pure-ftpd?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.49-4.1build1","1.0.50-2","1.0.50-2.1","1.0.50-2.1ubuntu0.22.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"pure-ftpd","binary_version":"1.0.50-2.1ubuntu0.22.04.1"},{"binary_version":"1.0.50-2.1ubuntu0.22.04.1","binary_name":"pure-ftpd-common"},{"binary_name":"pure-ftpd-ldap","binary_version":"1.0.50-2.1ubuntu0.22.04.1"},{"binary_name":"pure-ftpd-mysql","binary_version":"1.0.50-2.1ubuntu0.22.04.1"},{"binary_name":"pure-ftpd-postgresql","binary_version":"1.0.50-2.1ubuntu0.22.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40524.json"}},{"package":{"name":"pure-ftpd","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/pure-ftpd?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.50-2.1build1","1.0.50-2.1ubuntu1","1.0.50-2.2","1.0.50-2.2build1","1.0.50-2.2build2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.0.50-2.2build2","binary_name":"pure-ftpd"},{"binary_name":"pure-ftpd-common","binary_version":"1.0.50-2.2build2"},{"binary_name":"pure-ftpd-ldap","binary_version":"1.0.50-2.2build2"},{"binary_name":"pure-ftpd-mysql","binary_version":"1.0.50-2.2build2"},{"binary_name":"pure-ftpd-postgresql","binary_version":"1.0.50-2.2build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-40524.json"}},{"package":{"name":"pure-ftpd","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/pure-ftpd?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.50-2.2build3"],"ecosystem_specific":{"binaries":[{"binary_name":"pure-ftpd","binary_version":"1.0.50-2.2build3"},{"binary_name":"pure-ftpd-common","binary_version":"1.0.50-2.2build3"},{"binary_version":"1.0.50-2.2build3","binary_name":"pure-ftpd-ldap"},{"binary_name":"pure-ftpd-mysql","binary_version":"1.0.50-2.2build3"},{"bina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