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Vulnerabilities

Vulnerability · CVE-2021-41653

TP-Link tl-wr840n_firmware Improper Control of Generation of Code ('Code Injection')

Published Dec 8, 2021 · catalog updated Dec 8, 2021 · TP-Link

Patch now

CVE-2021-41653 is in the CISA known-exploited catalog. Confirm TP-Link against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
76.05%
Remediation
Remediation guidance
Affected products
vendor TP-Link tl-wr840n_firmware

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. Initial-access exploit intelligence.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor TP-Link tl-wr840n_firmwareversion unspecified

How to fix CVE-2021-41653

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-41653 is in the CISA known-exploited catalog. Confirm TP-Link against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS 76.05%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 8, 2021 · VulnCheck KEV

    Detected

    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. Initial-access exploit intelligence.

  2. Dec 8, 2021 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Sources

  • CVE.orgVulnerability recordCVE-2021-41653

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-41653

    30-day exploitation probability 76.0%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-2021-41653

    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.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.