Vulnerability-Lookup

OESA-2023-1882 (CVE-2021-37533)

Vulnerability from osv_openeuler – Published: 2023-12-01 11:06 – Updated: 2026-08-06 11:06 – Source website

Summary

apache-commons-net security update

Details

Apache Commons Net library contains a collection of network utilities and protocol implementations. Supported protocols include: Echo, Finger, FTP, NNTP, NTP, POP3(S), SMTP(S), Telnet, Whois

Security Fix(es):

Prior to Apache Commons Net 3.9.0, Net's FTP client trusts the host from PASV response by default. A malicious server can redirect the Commons Net code to use a different host, but the user has to connect to the malicious server in the first place. This may lead to leakage of information about services running on the private network of the client. The default in version 3.9.0 is now false to ignore such hosts, as cURL does. See https://issues.apache.org/jira/browse/NET-711.(CVE-2021-37533)

Severity

6.5 (Medium)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

References

URL

Type

	https://www.openeuler.org/en/security/safety-bull…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2021-37533	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "noarch": [
          "apache-commons-net-help-3.6-7.oe1.noarch.rpm",
          "apache-commons-net-3.6-7.oe1.noarch.rpm"
        ],
        "src": [
          "apache-commons-net-3.6-7.oe1.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP1",
        "name": "apache-commons-net",
        "purl": "pkg:rpm/openEuler/apache-commons-net\u0026distro=openEuler-20.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6-7.oe1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "apache-commons-net-help-3.6-7.oe1.noarch.rpm",
          "apache-commons-net-3.6-7.oe1.noarch.rpm"
        ],
        "src": [
          "apache-commons-net-3.6-7.oe1.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP3",
        "name": "apache-commons-net",
        "purl": "pkg:rpm/openEuler/apache-commons-net\u0026distro=openEuler-20.03-LTS-SP3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6-7.oe1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "apache-commons-net-help-3.6-7.oe2203.noarch.rpm",
          "apache-commons-net-3.6-7.oe2203.noarch.rpm",
          "apache-commons-net-3.6-7.oe2203sp1.noarch.rpm",
          "apache-commons-net-help-3.6-7.oe2203sp1.noarch.rpm",
          "apache-commons-net-3.6-7.oe2203sp2.noarch.rpm",
          "apache-commons-net-help-3.6-7.oe2203sp2.noarch.rpm"
        ],
        "src": [
          "apache-commons-net-3.6-7.oe2203.src.rpm",
          "apache-commons-net-3.6-7.oe2203sp1.src.rpm",
          "apache-commons-net-3.6-7.oe2203sp2.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS",
        "name": "apache-commons-net",
        "purl": "pkg:rpm/openEuler/apache-commons-net\u0026distro=openEuler-22.03-LTS"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6-7.oe2203sp2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "apache-commons-net-3.6-7.oe2203sp1.noarch.rpm",
          "apache-commons-net-help-3.6-7.oe2203sp1.noarch.rpm"
        ],
        "src": [
          "apache-commons-net-3.6-7.oe2203sp1.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP1",
        "name": "apache-commons-net",
        "purl": "pkg:rpm/openEuler/apache-commons-net\u0026distro=openEuler-22.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6-7.oe2203sp1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "apache-commons-net-3.6-7.oe2203sp2.noarch.rpm",
          "apache-commons-net-help-3.6-7.oe2203sp2.noarch.rpm"
        ],
        "src": [
          "apache-commons-net-3.6-7.oe2203sp2.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP2",
        "name": "apache-commons-net",
        "purl": "pkg:rpm/openEuler/apache-commons-net\u0026distro=openEuler-22.03-LTS-SP2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6-7.oe2203sp2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "Medium"
  },
  "details": "Apache Commons Net library contains a collection of network utilities and protocol implementations. Supported protocols include: Echo, Finger, FTP, NNTP, NTP, POP3(S), SMTP(S), Telnet, Whois\r\n\r\nSecurity Fix(es):\r\n\r\nPrior to Apache Commons Net 3.9.0, Net\u0026apos;s FTP client trusts the host from PASV response by default. A malicious server can redirect the Commons Net code to use a different host, but the user has to connect to the malicious server in the first place. This may lead to leakage of information about services running on the private network of the client. The default in version 3.9.0 is now false to ignore such hosts, as cURL does. See https://issues.apache.org/jira/browse/NET-711.(CVE-2021-37533)",
  "id": "OESA-2023-1882",
  "modified": "2026-08-06T11:06:19Z",
  "published": "2023-12-01T11:06:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2023-1882"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-37533"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "apache-commons-net security update",
  "upstream": [
    "CVE-2021-37533"
  ]
}

CVE-2021-37533 (GCVE-0-2021-37533)

Vulnerability from cvelistv5 – Published: 2022-12-03 00:00 – Updated: 2025-04-24 15:25

Title

Apache Commons Net's FTP client trusts the host from PASV response by default

Summary

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-04-24 15:24 UTC

CWE

CWE-20 - Improper Input Validation

Assigner

apache mitre root

References

4 references

URL	Tags
https://lists.apache.org/thread/o6yn9r9x6s94v9726…
http://www.openwall.com/lists/oss-security/2022/12/03/1	mailing-list
https://lists.debian.org/debian-lts-announce/2022…	mailing-list
https://www.debian.org/security/2022/dsa-5307	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache Commons Net	Affected: Apache Commons Net , < 3.9.0 (custom)

Credits

Apache Commons would like to thank ZeddYu Lu for reporting this issue.

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T01:23:01.166Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://lists.apache.org/thread/o6yn9r9x6s94v97264hmgol1sf48mvx7"
          },
          {
            "name": "[oss-security] 20221203 CVE-2021-37533: Apache Commons Net\u0027s FTP client trusts the host from PASV response by default",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2022/12/03/1"
          },
          {
            "name": "[debian-lts-announce] 20221229 [SECURITY] [DLA 3251-1] libcommons-net-java security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/12/msg00038.html"
          },
          {
            "name": "DSA-5307",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2022/dsa-5307"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 6.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "REQUIRED",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-37533",
                "options": [
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                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
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                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-04-24T15:24:58.397495Z",
                "version": "2.0.3"
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        ],
        "providerMetadata": {
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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        },
        "title": "CISA ADP Vulnrichment"
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    ],
    "cna": {
      "affected": [
        {
          "product": "Apache Commons Net",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "3.9.0",
              "status": "affected",
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            }
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        }
      ],
      "credits": [
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          "lang": "en",
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      "metrics": [
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              "other": "low"
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      "problemTypes": [
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          "descriptions": [
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              "description": "CWE-20 Improper Input Validation",
              "lang": "en",
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          "url": "https://www.debian.org/security/2022/dsa-5307"
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      ],
      "source": {
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        "discovery": "UNKNOWN"
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    "dateReserved": "2021-07-26T00:00:00.000Z",
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    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.