CVE-2021-29280Public exploit

Service interruption via poisoned ARP traffic

Published Aug 19, 2021 · Updated Aug 3, 2024

Buffer overflow in TP-Link Wireless N Router WR840N allows adjacent authenticated attackers to disrupt routing through ARP poisoning. Public records do not identify the affected firmware versions, memory-handling locus, or the ARP input that overruns the buffer. An attacker must reach the same LAN and satisfy the low-privilege gate; successful exploitation interrupts Internet access for the router and connected devices.

CVSS severity6.4
Medium
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in TP-Link Wireless N Router WR840N allows adjacent authenticated attackers to disrupt routing through ARP poisoning. Public records do not identify the affected firmware versions, memory-handling locus, or the ARP input that overruns the buffer. An attacker must reach the same LAN and satisfy the low-privilege gate; successful exploitation interrupts Internet access for the router and connected devices.

The record

CVE
CVE-2021-29280
Published
Aug 19, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-668, T1557.002
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.4NIST NVDCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
4.3NIST NVDAV:A/AC:M/Au:N/C:N/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1557.002Adversary-in-the-Middle: ARP Cache Poisoning

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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