CVE-2021-25646
Apache Druid includes the ability to execute user-provided JavaScript code embedded in various types of requests. This functionality is intended for use in high-trust environments, and is disabled by default. However, in Druid 0.20.0 and earlier, it is possible for an authenticated user to send a specially-crafted request that forces Druid to run user-provided JavaScript code for that request, regardless of server configuration. This can be leveraged to execute code on the target machine with the privileges of the Druid server process.
- CVSS
- 8.8High
- Exploited in the wild
- Not knownPublic exploit code; not in CISA KEV
- EPSS
- 99.1%chance of exploitation in the next 30 daystop 0.1% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 29 Jan 2021analysed here 12 Nov 2026
Summary
Triage
- Exploitable
- At runtime
- Attack vector
- network
- Can a WAF block it?
- Partly. See why
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Apache Software Foundation Apache Druid | >= 0.20.0 and earlier and <= 0.20.0Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- apache:druid
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. The bug can be reached over the network, so generic WAF rules may stop some attacks. Its weakness type is unknown, so we cannot be more precise.
Also consider: patch
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Not listed as of our last sync.
- Public exploit code
- Yes: 1 Metasploit module · 13 GitHub proofs of concept · 1 Nuclei template
Metasploit
- exploit/linux/http/apache_druid_js_rceexploit, rank excellent
Nuclei
- Apache Druid - Remote Code Executiondetection template, high
GitHub proofs of concept
- 1n7erface/PocList1,070 stars
- yaunsky/cve-2021-2564617 stars
- j2ekim/CVE-2021-256464 stars
- k7pro/CVE-2021-25646-exp4 stars
and 9 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 29 Jan 2021Published
- 3 Feb 2021First public exploit or proof of concept4 days later
- 13 Feb 2025CVE record last updated1,472 days (about 4 years) later
- 12 Nov 2026Analysed by vulneraibility.com637 days (about 2 years) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | LowThe attacker needs basic user privileges. | The attacker needs basic user privileges. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2021-25646 being exploited?
Not confirmed. CVE-2021-25646 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 99% probability of exploitation in the next 30 days.
How severe is CVE-2021-25646?
CVE-2021-25646 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2021-25646?
Yes. A fix has been recorded for CVE-2021-25646. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2021-25646 affect?
CVE-2021-25646 affects apache:druid. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
16 references in the CVE record, grouped by the tags the record gives them.
Other links (16)
- lists.apache.org /thread.html/rfda8a3aa6ac06a80c5cbfdeae0fc85f88a5984e32ea05e6dda46f866%40%3Cdev.
- openwall.com /lists/oss-security/2021/01/29/6
- lists.apache.org /thread.html/r64431c2b97209f566b5dff92415e7afba0ed3bfab4695ebaa8a62e5d%40%3Cdev.
- lists.apache.org /thread.html/rc167d5e57f3120578718a7a458ce3e73b3830ac4efbb1b085bd06b92%40%3Cdev.
- lists.apache.org /thread.html/r20e0c3b10ae2c05a3aad40f1476713c45bdefc32c920b9986b941d8f%40%3Canno
- lists.apache.org /thread.html/r4f84b542417ea46202867c0a8b3eaf3b4cfed30e09174a52122ba210%40%3Ccomm
Show 10 more
- lists.apache.org /thread.html/rea9436a4063927a567d698431ddae55e760c3f876c22ac5b9813685f%40%3Ccomm
- lists.apache.org /thread.html/r121abe8014d381943b63c60615149d40bde9dc1c868bcee90d0d0848%40%3Ccomm
- lists.apache.org /thread.html/rfeb775822cd3baef1595b60f6860f5ca849eb1903236483f3297bd5c%40%3Ccomm
- lists.apache.org /thread.html/r04fa1ba93599487c95a8497044d37f8c02a439bfcf92b4567bfb7c8f%40%3Ccomm
- lists.apache.org /thread.html/r87aa94e28dd21ee2252d30c63f01ab9cb5474ee5bdd98dd8d7d734aa%40%3Ccomm
- lists.apache.org /thread.html/r7dff4790e7a5c697fc0360adf11f5aeb31cd6ad80644fffee690673c%40%3Ccomm
- lists.apache.org /thread.html/ra4225912f501016bc5e0ac44e14b8d6779173a3a1dc7baacaabcc9ba%40%3Ccomm
- lists.apache.org /thread.html/r5ef625076982aee7d23c23f07717e626b73f421fba5154d1e4de15e1%40%3Ccomm
- lists.apache.org /thread.html/r443e2916c612fbd119839c0fc0729327d6031913a75081adac5b43ad%40%3Cdev.
- packetstormsecurity.com /files/162345/Apache-Druid-0.20.0-Remote-Command-Execution.html
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- FIRST EPSS: exploit probability and percentile
- Metasploit Framework: exploit and scanner modules
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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