CVE-2021-34203

{"containers": {"cna": {"affected": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "descriptions": [{"lang": "en", "value": "D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control. Router ac2600 (dir-2640-us), when setting PPPoE, will start quagga process in the way of whole network monitoring, and this function uses the original default password and port. An attacker can easily use telnet to log in, modify routing information, monitor the traffic of all devices under the router, hijack DNS and phishing attacks. In addition, this interface is likely to be questioned by customers as a backdoor, because the interface should not be exposed."}], "problemTypes": [{"descriptions": [{"description": "n/a", "lang": "en", "type": "text"}]}], "providerMetadata": {"dateUpdated": "2026-07-05T15:48:49.472Z", "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre"}, "references": [{"url": "https://www.dlink.com/en/security-bulletin/"}, {"url": "https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203"}], "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "cve@mitre.org", "ID": "CVE-2021-34203", "STATE": "PUBLIC"}, "affects": {"vendor": {"vendor_data": [{"product": {"product_data": [{"product_name": "n/a", "version": {"version_data": [{"version_value": "n/a"}]}}]}, "vendor_name": "n/a"}]}}, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": {"description_data": [{"lang": "eng", "value": "D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control. Router ac2600 (dir-2640-us), when setting PPPoE, will start quagga process in the way of whole network monitoring, and this function uses the original default password and port. An attacker can easily use telnet to log in, modify routing information, monitor the traffic of all devices under the router, hijack DNS and phishing attacks. In addition, this interface is likely to be questioned by customers as a backdoor, because the interface should not be exposed."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "n/a"}]}]}, "references": {"reference_data": [{"name": "http://d-link.com", "refsource": "MISC", "url": "http://d-link.com"}, {"name": "https://www.dlink.com/en/security-bulletin/", "refsource": "MISC", "url": "https://www.dlink.com/en/security-bulletin/"}, {"name": "http://dir-2640-us.com", "refsource": "MISC", "url": "http://dir-2640-us.com"}, {"name": "https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203", "refsource": "MISC", "url": "https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203"}]}}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-07-09T00:13:56.133Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://www.dlink.com/en/security-bulletin/"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203"}]}]}, "cveMetadata": {"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "cveId": "CVE-2021-34203", "datePublished": "2021-06-16T19:02:03.000Z", "dateReserved": "2021-06-07T00:00:00.000Z", "dateUpdated": "2026-07-09T00:13:56.133Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.2"}

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{"affected": [{"affectedData": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "source": "cve@mitre.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:dlink:dir-2640-us_firmware:1.01b04:*:*:*:*:*:*:*", "matchCriteriaId": "1E8DB0D1-B2E6-457A-A4A5-C6AE9EB82624", "vulnerable": true}], "negate": false, "operator": "OR"}, {"cpeMatch": [{"criteria": "cpe:2.3:h:dlink:dir-2640-us:-:*:*:*:*:*:*:*", "matchCriteriaId": "894C2BD1-B610-4F15-864E-92D6B515488D", "vulnerable": false}], "negate": false, "operator": "OR"}], "operator": "AND"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control. Router ac2600 (dir-2640-us), when setting PPPoE, will start quagga process in the way of whole network monitoring, and this function uses the original default password and port. An attacker can easily use telnet to log in, modify routing information, monitor the traffic of all devices under the router, hijack DNS and phishing attacks. In addition, this interface is likely to be questioned by customers as a backdoor, because the interface should not be exposed."}, {"lang": "es", "value": "D-Link DIR-2640-US versi\u00f3n 1.01B04 es vulnerable al Control de Acceso Incorrecto. El router ac2600 (dir-2640-us), cuando se configura PPPoE, iniciar\u00e1 el proceso quagga en la manera de monitorizaci\u00f3n de toda la red, y esta funci\u00f3n usa la contrase\u00f1a y el puerto originales predeterminado. Un atacante puede usar f\u00e1cilmente telnet para iniciar sesi\u00f3n, modificar la informaci\u00f3n de enrutamiento, monitorear el tr\u00e1fico de todos los dispositivos bajo el router, secuestrar el DNS y los ataques de phishing. Adem\u00e1s, es probable que esta interfaz sea cuestionada por los clientes como una puerta trasera, ya que la interfaz no deber\u00eda estar expuesta"}], "id": "CVE-2021-34203", "lastModified": "2026-07-09T01:16:55.557", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "LOW", "accessVector": "ADJACENT_NETWORK", "authentication": "NONE", "availabilityImpact": "NONE", "baseScore": 4.8, "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "vectorString": "AV:A/AC:L/Au:N/C:P/I:P/A:N", "version": "2.0"}, "exploitabilityScore": 6.5, "impactScore": 4.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "NONE", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.2, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2021-06-16T20:15:07.610", "references": [{"source": "cve@mitre.org", "tags": ["Exploit", "Third Party Advisory"], "url": "https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203"}, {"source": "cve@mitre.org", "tags": ["Vendor Advisory"], "url": "https://www.dlink.com/en/security-bulletin/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Exploit", "Third Party Advisory"], "url": "https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Vendor Advisory"], "url": "https://www.dlink.com/en/security-bulletin/"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1188"}], "source": "nvd@nist.gov", "type": "Primary"}]}

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