CVE-2021-33564
Medium PUBLISHEDAn 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...
Not yet in CISA KEV
Recommended Action
Review exposure in your environment and monitor for exploitation signals before broader rollout.
At a Glance
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
- May 29, 2021
- First Seen
- Jul 01, 2025
- CVSS
- 9.8 Critical
- EPSS
- —
Recommended Actions
- Review exposure in your environment and monitor for exploitation signals before broader rollout.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
| Source | Added |
|---|---|
| The Shadowserver (via CIRCL) First | 2025-07-01 00:00 UTC |
References
- https://github.com/markevans/dragonfly/issues/513
- https://github.com/markevans/dragonfly/commit/25399297bb457f7fcf8e3f91e85945b255b111b5
- https://github.com/markevans/dragonfly/compare/v1.3.0...v1.4.0
- https://raw.githubusercontent.com/projectdiscovery/nuclei-templates/master/cves/2021/CVE-2021-33564.yaml
- https://github.com/mlr0p/CVE-2021-33564
- https://zxsecurity.co.nz/research/argunment-injection-ruby-dragonfly/
Detection Context
Request patterns and scanner artifacts observed for this CVE. Operational detection logic guidance is coming soon.
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-33564.yaml | Apr 25, 2025 |
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:N/AC:M/Au:N/C:P/I:P/A:P
Exploitation Status
Proof of concept available
Recorded 2021-05-25 02:48:08 UTC · GitHub
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-33564.yaml | Apr 25, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2021-05-25 02:48:08 UTC · 16 stars
Argument Injection in Dragonfly Ruby Gem
nuclei · Created Unknown
Timeline
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Added to KEVIntel
-
Detected by Nuclei
-
CVE Published to Public
-
Proof of Concept Exploit Available
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CVE ID Reserved
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v1/pro/kevs/CVE-2021-33564
{
"cve_id": "CVE-2021-33564",
"title": "An argument injection vulnerability in the Dragonfly gem before 1.4.0 for Rub...",
"affected_vendor": "markevans",
"affected_product": "Dragonfly",
"confidence": "Medium",
"cvss_score": 9.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": false,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}