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CVE Record

CVE-2021-41653: The PING function on the TP-Link TL-WR840N EU v5 router with firmware through TL-WR840N(EU)_V5_171211 is vu...

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2021-41653 is a remote code execution issue in the TP-Link TL-WR840N EU v5 router. The vulnerable area is the router’s Ping diagnostic function, where a crafted IP address input can execute code. The source bundle does not provide CVSS, patch details, authentication requirements, or confirmed exploitation.

Executive priority

Treat this as a high-priority edge-device risk if affected routers are present. The business concern is unauthorized control of a network gateway. Prioritize inventory, isolation of management access, and vendor-confirmed remediation before routine maintenance windows.

Technical view

The CVE describes command execution through crafted input submitted to the Ping function’s IP address field on TL-WR840N EU v5 firmware through TL-WR840N(EU)_V5_171211. Available sources identify the vulnerable function and affected firmware ceiling, but do not document exploit preconditions, privilege requirements, or fixed versions.

Likely exposure

Exposure is likely limited to TP-Link TL-WR840N EU v5 devices running firmware through TL-WR840N(EU)_V5_171211. Risk increases if the router management interface or diagnostic Ping function is reachable from untrusted networks. The bundle does not prove internet-wide exposure.

Exploitation context

The CVE is not marked as CISA KEV in the provided bundle, and no cited source confirms active exploitation. A public researcher reference exists, so defenders should assume technical details may be discoverable, while avoiding claims of exploitation without stronger evidence.

Researcher notes

Key missing evidence includes CVSS scoring, CWE classification, authentication requirements, fixed firmware version, and exploitation status. Analysis should remain bounded to the described Ping input RCE on TL-WR840N EU v5 firmware through the named version.

Mitigation direction

  • Inventory TL-WR840N EU v5 routers and record firmware versions.
  • Check TP-Link guidance for firmware updates or replacement advice.
  • Restrict router administration to trusted management networks only.
  • Disable remote administration where it is not required.
  • Replace unsupported devices if no fixed firmware is available.

Validation and detection

  • Confirm whether any device is TL-WR840N EU hardware version v5.
  • Compare firmware against TL-WR840N(EU)_V5_171211 or earlier.
  • Verify management interfaces are not exposed to untrusted networks.
  • Review router logs and configuration for unexpected administrative changes.
  • Document remediation status for each identified device.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2021-41653 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
1ADP providers
3Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.