CVE-2021-3287
High PUBLISHEDZoho ManageEngine OpManager before 12.5.329 allows unauthenticated Remote Code Execution due to a general bypass in the deserialization class.
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
Zoho ManageEngine OpManager before 12.5.329 allows unauthenticated Remote Code Execution due to a general bypass in the deserialization class.
- CVE Published
- Apr 22, 2021
- Exploitation Reported
- Apr 22, 2021
- CVSS
- 9.8 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
n/a
|
n/a |
Affected |
CVE References
- manageengine.com/network-monitoring/help/read-me-complete.html manageengine.com · CVE Record https://www.manageengine.com/network-monitoring/help/read-me-complete...
- packetstormsecurity.com/files/164231/ManageEngine-OpManager-SumPDU-J... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/164231/ManageEngine-OpManager-Su...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- 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.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2021-04-22 12:58 UTC |
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-2021-3287.yaml | Jun 01, 2026 |
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/opmanager_sumpdu_deserialization.rb | Apr 28, 2025 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:N/AC:L/Au:N/C:P/I:P/A:P
Exploitation Status
Exploited in the wild
Recorded 2021-04-22 12:58:00 UTC · The Shadowserver
Proof of concept available
Recorded 2025-04-28 15:02:20 UTC · Nuclei Templates
Weaknesses (CWE)
-
Deserialization of Untrusted Data
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-3287.yaml | Jun 01, 2026 |
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/opmanager_sumpdu_deserialization.rb | Apr 28, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
15:34 UTC about 2 months ago15:34 UTC · about 2 months ago
Nuclei template available
Scanner coverage available
-
15:02 UTC about 1 year ago15:02 UTC · about 1 year ago
Metasploit module available
Exploit module available
-
15:02 UTC about 1 year ago15:02 UTC · about 1 year ago
Public PoC available
Public proof-of-concept code published
-
12:58 UTC about 5 years ago12:58 UTC · about 5 years ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
12:58 UTC about 5 years ago12:58 UTC · about 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
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/v2/pro/kevs/CVE-2021-3287
{
"cve_id": "CVE-2021-3287",
"title": "Zoho ManageEngine OpManager before 12.5.329 allows unauthenticated Remote Cod...",
"affected_vendor": "Zoho",
"affected_product": "ManageEngine OpManager",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "High",
"cvss_score": 9.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}