msrc_cve-2023-51764
Vulnerability from csaf_microsoft
Published
2023-12-01 08:00
Modified
2024-06-30 07:00
Summary
Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address allowing bypass of an SPF protection mechanism. This occurs because Postfix supports <LF>.<CR><LF> but some other popular e-mail servers do not. To prevent attack variants (by always disallowing <LF> without <CR>) a different solution is required such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23 3.6.13 3.7.9 3.8.4 or 3.9.

Notes

Additional Resources
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
Disclaimer
The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.


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{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2023-51764 Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address allowing bypass of an SPF protection mechanism. This occurs because Postfix supports \u003cLF\u003e.\u003cCR\u003e\u003cLF\u003e but some other popular e-mail servers do not. To prevent attack variants (by always disallowing \u003cLF\u003e without \u003cCR\u003e) a different solution is required such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23 3.6.13 3.7.9 3.8.4 or 3.9. - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2023/msrc_cve-2023-51764.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address allowing bypass of an SPF protection mechanism. This occurs because Postfix supports \u003cLF\u003e.\u003cCR\u003e\u003cLF\u003e but some other popular e-mail servers do not. To prevent attack variants (by always disallowing \u003cLF\u003e without \u003cCR\u003e) a different solution is required such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23 3.6.13 3.7.9 3.8.4 or 3.9.",
    "tracking": {
      "current_release_date": "2024-06-30T07:00:00.000Z",
      "generator": {
        "date": "2025-10-20T00:49:37.100Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2023-51764",
      "initial_release_date": "2023-12-01T08:00:00.000Z",
      "revision_history": [
        {
          "date": "2024-01-06T00:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2024-06-30T07:00:00.000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "2.0",
                "product": {
                  "name": "CBL Mariner 2.0",
                  "product_id": "17086"
                }
              },
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003ccbl2 postfix 3.7.4-1",
                "product": {
                  "name": "\u003ccbl2 postfix 3.7.4-1",
                  "product_id": "2"
                }
              },
              {
                "category": "product_version",
                "name": "cbl2 postfix 3.7.4-1",
                "product": {
                  "name": "cbl2 postfix 3.7.4-1",
                  "product_id": "19749"
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003ccbl2 postfix 3.7.0-3",
                "product": {
                  "name": "\u003ccbl2 postfix 3.7.0-3",
                  "product_id": "4"
                }
              },
              {
                "category": "product_version",
                "name": "cbl2 postfix 3.7.0-3",
                "product": {
                  "name": "cbl2 postfix 3.7.0-3",
                  "product_id": "18197"
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003cazl3 postfix 3.9.0-1",
                "product": {
                  "name": "\u003cazl3 postfix 3.9.0-1",
                  "product_id": "3"
                }
              },
              {
                "category": "product_version",
                "name": "azl3 postfix 3.9.0-1",
                "product": {
                  "name": "azl3 postfix 3.9.0-1",
                  "product_id": "18198"
                }
              },
              {
                "category": "product_version_range",
                "name": "\u003cazl3 postfix 3.7.0-2",
                "product": {
                  "name": "\u003cazl3 postfix 3.7.0-2",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "azl3 postfix 3.7.0-2",
                "product": {
                  "name": "azl3 postfix 3.7.0-2",
                  "product_id": "19753"
                }
              }
            ],
            "category": "product_name",
            "name": "postfix"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccbl2 postfix 3.7.4-1 as a component of CBL Mariner 2.0",
          "product_id": "17086-2"
        },
        "product_reference": "2",
        "relates_to_product_reference": "17086"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "cbl2 postfix 3.7.4-1 as a component of CBL Mariner 2.0",
          "product_id": "19749-17086"
        },
        "product_reference": "19749",
        "relates_to_product_reference": "17086"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003ccbl2 postfix 3.7.0-3 as a component of CBL Mariner 2.0",
          "product_id": "17086-4"
        },
        "product_reference": "4",
        "relates_to_product_reference": "17086"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "cbl2 postfix 3.7.0-3 as a component of CBL Mariner 2.0",
          "product_id": "18197-17086"
        },
        "product_reference": "18197",
        "relates_to_product_reference": "17086"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003cazl3 postfix 3.9.0-1 as a component of Azure Linux 3.0",
          "product_id": "17084-3"
        },
        "product_reference": "3",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 postfix 3.9.0-1 as a component of Azure Linux 3.0",
          "product_id": "18198-17084"
        },
        "product_reference": "18198",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003cazl3 postfix 3.7.0-2 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 postfix 3.7.0-2 as a component of Azure Linux 3.0",
          "product_id": "19753-17084"
        },
        "product_reference": "19753",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2023-51764",
      "cwe": {
        "id": "CWE-345",
        "name": "Insufficient Verification of Data Authenticity"
      },
      "notes": [
        {
          "category": "general",
          "text": "mitre",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "19749-17086",
          "18197-17086",
          "18198-17084",
          "19753-17084"
        ],
        "known_affected": [
          "17086-2",
          "17086-4",
          "17084-3",
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2023-51764 Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address allowing bypass of an SPF protection mechanism. This occurs because Postfix supports \u003cLF\u003e.\u003cCR\u003e\u003cLF\u003e but some other popular e-mail servers do not. To prevent attack variants (by always disallowing \u003cLF\u003e without \u003cCR\u003e) a different solution is required such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23 3.6.13 3.7.9 3.8.4 or 3.9. - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2023/msrc_cve-2023-51764.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2024-01-06T00:00:00.000Z",
          "details": "3.7.0-3:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "17086-2",
            "17086-4"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        },
        {
          "category": "vendor_fix",
          "date": "2024-01-06T00:00:00.000Z",
          "details": "3.9.0-1:Security Update:https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade",
          "product_ids": [
            "17084-3",
            "17084-1"
          ],
          "url": "https://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "environmentalsScore": 0.0,
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "temporalScore": 5.3,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "17086-2",
            "17086-4",
            "17084-3",
            "17084-1"
          ]
        }
      ],
      "title": "Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address allowing bypass of an SPF protection mechanism. This occurs because Postfix supports \u003cLF\u003e.\u003cCR\u003e\u003cLF\u003e but some other popular e-mail servers do not. To prevent attack variants (by always disallowing \u003cLF\u003e without \u003cCR\u003e) a different solution is required such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23 3.6.13 3.7.9 3.8.4 or 3.9."
    }
  ]
}


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