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VDE-2021-012

Vulnerability from csaf_mbconnectlinegmbh - Published: 2021-04-26 08:04 - Updated: 2025-05-14 12:28
Summary
MB connect line: multiple products partially affected by DNSpooq
Notes
Summary: Multiple issues have been identified in dnsmasq < 2.83
Impact: Please see the CVE-IDs for details.
Remediation: Update to the following versions: | Product | Fixed Version | |--------------------|-------------------| | mbNET/mbNET .rokey | >= 7.0.0 | | mbNET HW1 | >= 5.1.11 |
CVE-2020-25684

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE-358 - Improperly Implemented Security Check for Standard
Vendor Fix Update to the following versions: | Product | Fixed Version | |--------------------|-------------------| | mbNET/mbNET .rokey | >= 7.0.0 | | mbNET HW1 | >= 5.1.11 |
Affected products
Product Identifier Version Remediation
mbNET HW1 <=5.1.10
MB connect line / Software / mbNET HW1
 <=5.1.10
mbNET/mbNET .rokey <=6.2.5
MB connect line / Software / mbNET/mbNET .rokey
 <=6.2.5
Product Identifier Version Remediation
mbNET HW1 5.1.11
MB connect line / Software / mbNET HW1
 5.1.11
mbNET/mbNET .rokey 7.0.0
MB connect line / Software / mbNET/mbNET .rokey
 7.0.0
CVE-2020-25685

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE-326 - Inadequate Encryption Strength
Vendor Fix Update to the following versions: | Product | Fixed Version | |--------------------|-------------------| | mbNET/mbNET .rokey | >= 7.0.0 | | mbNET HW1 | >= 5.1.11 |
Affected products
Known affected 2 products, the same list as for CVE-2020-25684
Fixed 2 products, the same list as for CVE-2020-25684
CVE-2020-25686

A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE-358 - Improperly Implemented Security Check for Standard
Vendor Fix Update to the following versions: | Product | Fixed Version | |--------------------|-------------------| | mbNET/mbNET .rokey | >= 7.0.0 | | mbNET HW1 | >= 5.1.11 |
Affected products
Known affected 2 products, the same list as for CVE-2020-25684
Fixed 2 products, the same list as for CVE-2020-25684
References
Acknowledgments
CERT@VDE certvde.com
To clipboard 

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        "summary": "coordination",
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    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
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        "category": "summary",
        "text": "Multiple issues have been identified in dnsmasq \u003c 2.83",
        "title": "Summary"
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      {
        "category": "description",
        "text": "Please see the CVE-IDs for details.",
        "title": "Impact"
      },
      {
        "category": "description",
        "text": "Update to the following versions:\n\n| Product            | Fixed Version |\n|--------------------|-------------------|\n| mbNET/mbNET .rokey | \u003e= 7.0.0         |\n| mbNET HW1         | \u003e= 5.1.11         |\n",
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        "category": "self",
        "summary": "VDE-2021-012: MB connect line: multiple products partially affected by DNSpooq - HTML",
        "url": "https://certvde.com/en/advisories/VDE-2021-012"
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      {
        "category": "self",
        "summary": "VDE-2021-012: MB connect line: multiple products partially affected by DNSpooq - CSAF",
        "url": "https://mbconnectline.csaf-tp.certvde.com/.well-known/csaf/white/2021/vde-2021-012.json"
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    "title": "MB connect line: multiple products partially affected by DNSpooq",
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                      "product_id": "CSAFPID-51001"
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  "vulnerabilities": [
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      "cve": "CVE-2020-25684",
      "cwe": {
        "id": "CWE-358",
        "name": "Improperly Implemented Security Check for Standard"
      },
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query\u0027s attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.",
          "title": "Vulnerability Description"
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          "details": "Update to the following versions:\n\n| Product            | Fixed Version |\n|--------------------|-------------------|\n| mbNET/mbNET .rokey | \u003e= 7.0.0         |\n| mbNET HW1         | \u003e= 5.1.11         |\n",
          "group_ids": [
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      ],
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            "attackVector": "NETWORK",
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            "baseScore": 3.7,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "environmentalScore": 3.7,
            "environmentalSeverity": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
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            "userInteraction": "NONE",
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            "version": "3.1"
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          "products": [
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            "CSAFPID-51002"
          ]
        }
      ],
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    },
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      "cwe": {
        "id": "CWE-326",
        "name": "Inadequate Encryption Strength"
      },
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.",
          "title": "Vulnerability Description"
        }
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          "group_ids": [
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            "attackVector": "NETWORK",
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            "confidentialityImpact": "NONE",
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            "integrityImpact": "LOW",
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            "CSAFPID-51002"
          ]
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      ],
      "title": "CVE-2020-25685"
    },
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      "cwe": {
        "id": "CWE-358",
        "name": "Improperly Implemented Security Check for Standard"
      },
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the \"Birthday Attacks\" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.",
          "title": "Vulnerability Description"
        }
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          "CSAFPID-52002"
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          "group_ids": [
            "CSAFGID-0001"
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            "CSAFPID-51002"
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      ],
      "title": "CVE-2020-25686"
    }
  ]
}



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