« Back to list

CVE-2022-43636

Status: ModifiedHigh (8.8)—

This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of TP-Link TL-WR940N 6_211111 3.20.1(US) routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the httpd service, which listens on TCP port 80 by default. The issue results from the lack of sufficient randomness in the sequnce numbers used for session managment. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-18334.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Tp-link — Tl-wr940n Firmware

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2022-43636",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2022-43636",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-02-12T17:41:19.538440Z"
        }
      }
    ],
    "cvssMetricV30": [
      {
        "type": "Secondary",
        "source": "zdi-disclosures@trendmicro.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.0",
          "baseScore": 7.5,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.6
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "zdi-disclosures@trendmicro.com",
      "affectedData": [
        {
          "vendor": "TP-Link",
          "product": "TL-WR940N",
          "versions": [
            {
              "status": "affected",
              "version": "6_211111 3.20.1(US)"
            }
          ]
        }
      ]
    }
  ],
  "published": "2023-03-29T19:15:20.410",
  "references": [
    {
      "url": "https://www.zerodayinitiative.com/advisories/ZDI-22-1614/",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "zdi-disclosures@trendmicro.com"
    },
    {
      "url": "https://www.zerodayinitiative.com/advisories/ZDI-22-1614/",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "zdi-disclosures@trendmicro.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-330"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of TP-Link TL-WR940N 6_211111 3.20.1(US) routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the httpd service, which listens on TCP port 80 by default. The issue results from the lack of sufficient randomness in the sequnce numbers used for session managment. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-18334."
    }
  ],
  "lastModified": "2026-06-17T05:07:00.140",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:tp-link:tl-wr940n_firmware:6_211111_3.20.1:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0E3EA13F-802C-4081-99D0-CE22758FCF32"
            }
          ],
          "operator": "OR"
        },
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:h:tp-link:tl-wr940n:-:*:*:*:*:*:*:*",
              "vulnerable": false,
              "matchCriteriaId": "93A1F9B1-C0C1-4FCC-AFD3-936E74ED6EA4"
            }
          ],
          "operator": "OR"
        }
      ],
      "operator": "AND"
    }
  ],
  "sourceIdentifier": "zdi-disclosures@trendmicro.com"
}