{"id":"CVE-2021-40524","aliases":["DEBIAN-CVE-2021-40524","DLA-4360-1","EUVD-2021-27700","GHSA-p53v-96v3-p5jg","UBUNTU-CVE-2021-40524","openSUSE-SU-2024:11773-1"],"status":"published","title":"In Pure-FTPd 1.0.49, an incorrect max_filesize quota mechanism in the server allows attackers to...","description":"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.)","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.04285,"percentile":0.91234,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-434"],"published":"2021-09-05T18:26:26Z","modified":"2026-10-23T18:02:30Z","exploits":[{"source":"nuclei","id":"CVE-2021-40524","title":"Pure-FTPd 1.0.23 \u003c 1.0.50 - Arbitrary File Upload","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/network/cves/2021/CVE-2021-40524.yaml"}],"fixes":[{"ecosystem":"Debian:12","package":"pure-ftpd","fixed_in":["1.0.50-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"pure-ftpd","fixed_in":["1.0.50-1"],"sources":["osv"]},{"ecosystem":"Debian:11","package":"pure-ftpd","fixed_in":["1.0.49-4.1+deb11u1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.50-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.50-1"}]}]},{"source":"osv","ecosystem":"Debian:11","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.49-4.1+deb11u1"}]}],"versions":["1.0.49-4.1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"pure-ftpd","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"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.46-1","1.0.46-1build1","1.0.46-1ubuntu18.04.1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"pure-ftpd","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"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"pure-ftpd","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"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"pure-ftpd","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"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.50-2.2build3"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.50-2.2build3","1.0.50-2.2build4"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"pure-ftpd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.50-1.1"}]}],"bundled":4}],"products":[{"vendor":"pureftpd","product":"pure-ftpd"}],"references":[{"url":"https://github.com/jedisct1/pure-ftpd/pull/158","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence","report"]},{"url":"https://github.com/jedisct1/pure-ftpd/compare/1.0.49...1.0.50","tags":["x_refsource_CONFIRM","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://github.com/jedisct1/pure-ftpd/commit/37ad222868e52271905b94afea4fc780d83294b4","tags":["x_refsource_CONFIRM","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/11/msg00003.html","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-40524"},{"url":"https://github.com/advisories/GHSA-p53v-96v3-p5jg"},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-40524","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-40524","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-40524","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2019-20176","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-9274","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-9365","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-40524","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-40524","description":"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.)","status":"published","published":"2021-09-05T18:26:26Z","modified":"2025-11-04T00:12:03.856Z","updated_at":"2026-11-02T14:33:01.495293Z"}],"euvd":[{"id":"EUVD-2021-27700","description":"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.)","status":"published","published":"2021-09-05T18:26:26Z","modified":"2025-11-04T00:12:03Z","updated_at":"2026-11-02T19:49:29.391161Z"}],"ghsa":[{"id":"GHSA-p53v-96v3-p5jg","title":"In Pure-FTPd 1.0.49, an incorrect max_filesize quota mechanism in the server allows attackers to...","description":"In Pure-FTPd 1.0.49, 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.","status":"published","published":"2022-05-24T19:13:01Z","modified":"2025-11-04T03:30:24Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T15:04:32.843339Z"}],"nvd":[{"id":"CVE-2021-40524","description":"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.)","status":"published","published":"2021-09-05T19:15:15.08Z","modified":"2026-06-17T04:07:05.163Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:06:58.05696Z"}],"osv":[{"id":"CVE-2021-40524","description":"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.)","status":"published","published":"2021-09-05T19:15:15.08Z","modified":"2026-10-20T14:08:49.20501561Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:21.249056Z"},{"id":"DEBIAN-CVE-2021-40524","description":"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.)","status":"published","published":"2021-09-05T19:15:15.08Z","modified":"2026-10-23T18:02:30.74517016Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:35.521549Z"},{"id":"UBUNTU-CVE-2021-40524","description":"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.)","status":"published","published":"2021-09-05T19:15:00Z","modified":"2026-05-20T16:05:09.542356589Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:29.220315Z"},{"id":"DLA-4360-1","title":"pure-ftpd - security update","status":"published","published":"2025-11-03T00:00:00Z","modified":"2025-11-03T22:17:32.551016Z","updated_at":"2026-11-02T15:46:12.7027Z"},{"id":"openSUSE-SU-2024:11773-1","title":"pure-ftpd-1.0.50-1.1 on GA media","description":"These are all security issues fixed in the pure-ftpd-1.0.50-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2024-06-15T00:00:00Z","modified":"2026-02-04T03:54:55.543403Z","updated_at":"2026-11-02T16:58:35.195147Z"}]}}