{"id":"CVE-2021-33564","aliases":["GHSA-j858-xp5v-f8xx"],"url":"https://o3.security/vulnerability/CVE-2021-33564","summary":"Dragonfly contains remote code execution vulnerability","details":"An argument injection vulnerability in the Dragonfly gem before 1.4.0 for Ruby allows remote attackers to read and write to arbitrary files via a crafted URL when the verify_url option is disabled. This may lead to code execution. The problem occurs because the generate and process features mishandle use of the ImageMagick convert utility.","published":"2021-05-29T14:15:08.510Z","modified":"2026-07-08T22:14:02.570529Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.72143,"percentile":0.99403,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":7,"affectedPackages":[{"ecosystem":"RubyGems","name":"dragonfly","fixedVersion":"1.4.0"}],"fix":{"url":"https://github.com/markevans/dragonfly/commit/25399297bb457f7fcf8e3f91e85945b255b111b5","label":"markevans/dragonfly@2539929"},"references":[{"type":"REPORT","url":"https://github.com/markevans/dragonfly/issues/513"},{"type":"FIX","url":"https://github.com/markevans/dragonfly/commit/25399297bb457f7fcf8e3f91e85945b255b111b5"},{"type":"FIX","url":"https://github.com/markevans/dragonfly/compare/v1.3.0...v1.4.0"},{"type":"EVIDENCE","url":"https://github.com/mlr0p/CVE-2021-33564"},{"type":"EVIDENCE","url":"https://raw.githubusercontent.com/projectdiscovery/nuclei-templates/master/cves/2021/CVE-2021-33564.yaml"},{"type":"EVIDENCE","url":"https://zxsecurity.co.nz/research/argunment-injection-ruby-dragonfly/"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33564"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-j858-xp5v-f8xx"},{"type":"WEB","url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/dragonfly/CVE-2021-33564.yml"},{"type":"WEB","url":"https://zxsecurity.co.nz/research/argunment-injection-ruby-dragonfly"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T22:14:02.570529Z"}}