FKIE_CVE-2023-36673

Vulnerability from fkie_nvd - Published: 2023-08-09 23:15 - Updated: 2026-06-17 06:06
Severity
7.3 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Summary
An issue was discovered in Avira Phantom VPN through 2.23.1 for macOS. The VPN client insecurely configures the operating system such that all IP traffic to the VPN server's IP address is sent in plaintext outside the VPN tunnel, even if this traffic is not generated by the VPN client, while simultaneously using plaintext DNS to look up the VPN server's IP address. This allows an adversary to trick the victim into sending traffic to arbitrary IP addresses in plaintext outside the VPN tunnel. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to "ServerIP attack, combined with DNS spoofing, that can leak traffic to an arbitrary IP address" rather than to only Avira Phantom VPN.
References
cve@mitre.orghttps://psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0015
cve@mitre.orghttps://tunnelcrack.mathyvanhoef.com/details.htmlExploit, Third Party Advisory
cve@mitre.orghttps://www.avira.com/en/free-vpnProduct
af854a3a-2127-422b-91ae-364da2661108https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0015
af854a3a-2127-422b-91ae-364da2661108https://tunnelcrack.mathyvanhoef.com/details.htmlExploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.avira.com/en/free-vpnProduct
Impacted products
Vendor Product Version
avira phantom_vpn *
To clipboard 

{
  "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:a:avira:phantom_vpn:*:*:*:*:*:macos:*:*",
              "matchCriteriaId": "73C5025B-A00A-488A-B9BC-9BD0834414CA",
              "versionEndIncluding": "2.23.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in Avira Phantom VPN through 2.23.1 for macOS. The VPN client insecurely configures the operating system such that all IP traffic to the VPN server\u0027s IP address is sent in plaintext outside the VPN tunnel, even if this traffic is not generated by the VPN client, while simultaneously using plaintext DNS to look up the VPN server\u0027s IP address. This allows an adversary to trick the victim into sending traffic to arbitrary IP addresses in plaintext outside the VPN tunnel. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to \"ServerIP attack, combined with DNS spoofing, that can leak traffic to an arbitrary IP address\" rather than to only Avira Phantom VPN."
    }
  ],
  "id": "CVE-2023-36673",
  "lastModified": "2026-06-17T06:06:48.537",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.1,
        "impactScore": 5.2,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2023-36673",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-10-10T18:37:16.766004Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2023-08-09T23:15:10.897",
  "references": [
    {
      "source": "cve@mitre.org",
      "url": "https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0015"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://tunnelcrack.mathyvanhoef.com/details.html"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Product"
      ],
      "url": "https://www.avira.com/en/free-vpn"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0015"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://tunnelcrack.mathyvanhoef.com/details.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Product"
      ],
      "url": "https://www.avira.com/en/free-vpn"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-319"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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