CVE-2021-41653
High PUBLISHEDThe PING function on the TP-Link TL-WR840N EU v5 router with firmware through TL-WR840N(EU)_V5_171211 is vulnerable to remote code execution via a...
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
The PING function on the TP-Link TL-WR840N EU v5 router with firmware through TL-WR840N(EU)_V5_171211 is vulnerable to remote code execution via a crafted payload in an IP address input field.
- CVE Published
- Nov 13, 2021
- Exploitation Reported
- Jul 08, 2026
- CVSS
- 9.8 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
n/a
|
n/a |
Affected |
CVE References
- tp-link.com/us/press/security-advisory tp-link.com · CVE Record https://www.tp-link.com/us/press/security-advisory/
- k4m1ll0.com/cve-2021-41653.html k4m1ll0.com · CVE Record https://k4m1ll0.com/cve-2021-41653.html
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 | 2025-09-18 00:00 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-2021-41653.yaml | Apr 25, 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:C/I:C/A:C
Exploitation Status
Exploited in the wild
Recorded 2026-07-08 00:00:00 UTC · The Shadowserver
Proof of concept available
Recorded 2021-11-29 06:39:43 UTC · GitHub
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-41653.yaml | Apr 25, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2021-11-29 06:39:43 UTC · 0 stars
TP-Link TL-WR840N EU v5 Remote Code Execution
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC 10 months ago00:00 UTC · 10 months ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
00:00 UTC about 1 year ago00:00 UTC · about 1 year ago
Nuclei template available
Scanner coverage available
-
06:39 UTC over 4 years ago06:39 UTC · over 4 years ago
Public PoC available
Public proof-of-concept code published
-
14:18 UTC over 4 years ago14:18 UTC · over 4 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC almost 5 years ago00:00 UTC · almost 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-2021-41653
{
"cve_id": "CVE-2021-41653",
"title": "The PING function on the TP-Link TL-WR840N EU v5 router with firmware through...",
"affected_vendor": "TP-Link",
"affected_product": "TL-WR840N EU v5 router",
"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": [ "..." ]
}