---
id: CVE-2022-25062
title: >-
  TP-LINK TL-WR840N(ES)_V6.20_180709 was discovered to contain an integer
  overflow via the function dm_checkString
summary: >-
  TP-LINK TL-WR840N(ES)_V6.20_180709 was discovered to contain an integer
  overflow via the function dm_checkString. This vulnerability allows attackers
  to cause a Denial of Service (DoS) via a crafted HTTP request.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-190
vendor: tp-link
product: tl-wr840n_firmware
affected:
  - tl-wr840n_firmware = 6.20_180709
published: '2022-02-25'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-25062'
references:
  - url: >-
      https://east-trowel-102.notion.site/CVE-2021-XXXX-RCE-Integer-Overflow-via-crafted-payload-in-an-DNS-input-field-userDomain-EN-2bc0fafd23224a5a8f86f5f0f9377d3d
    label: cve@mitre.org
  - url: 'http://router.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'http://tp-link.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://east-trowel-102.notion.site/CVE-2021-XXXX-RCE-Integer-Overflow-via-crafted-payload-in-an-DNS-input-field-userDomain-EN-2bc0fafd23224a5a8f86f5f0f9377d3d
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - exploit-available
epss: 0.03503
epssPercentile: 0.8873
ingestedAt: '2026-07-06T02:09:23.246Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/exploitwritter/CVE-2022-25062'
  checkedAt: '2026-09-26T09:05:27.807Z'
exploitAvailable: true
---

## Overview

TP-LINK TL-WR840N(ES)_V6.20_180709 was discovered to contain an integer overflow via the function dm_checkString. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted HTTP request.

## Affected

- `tl-wr840n_firmware = 6.20_180709`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.