Vulnerability-Lookup

UBUNTU-CVE-2021-3761 (CVE-2021-3761)

Vulnerability from osv_ubuntu – Published: 2021-09-09 14:15 – Updated: 2025-07-16 04:56 – Source website

Withdrawn 2025-07-18

Details

Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as "RPKI invalid". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.

Severity

7.5 (High)


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

7.5 (High)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-3761	REPORT
	https://github.com/cloudflare/cfrpki/security/adv…	REPORT
	https://github.com/cloudflare/cfrpki/commit/a8db4…	REPORT
	https://www.cve.org/CVERecord?id=CVE-2021-3761	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "octorpki",
            "binary_version": "1.4.2-1"
          },
          {
            "binary_name": "octorpki-dbgsym",
            "binary_version": "1.4.2-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "cfrpki",
        "purl": "pkg:deb/ubuntu/cfrpki@1.4.2-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.2-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.2-1",
        "1.3.0-1",
        "1.4.0-1"
      ]
    }
  ],
  "aliases": [],
  "details": "Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.",
  "id": "UBUNTU-CVE-2021-3761",
  "modified": "2025-07-16T04:56:46Z",
  "published": "2021-09-09T14:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3761"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/cloudflare/cfrpki/commit/a8db4e009ef217484598ba1fd1c595b54e0f6422"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-3761"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-3761"
  ],
  "withdrawn": "2025-07-18T16:46:29Z"
}

CVE-2021-3761 (GCVE-0-2021-3761)

Vulnerability from cvelistv5 – Published: 2021-09-09 14:05 – Updated: 2024-09-17 02:56

Title

OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values

Summary

Severity

7.5 (High)


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

CWE

Missing out of bounds check

Assigner

cloudflare mitre root

References

2 references

URL	Tags
https://github.com/cloudflare/cfrpki/security/adv…	x_refsource_MISC
https://www.debian.org/security/2022/dsa-5041	vendor-advisoryx_refsource_DEBIAN

Impacted products

1 product

Vendor	Product	Version
Cloudflare	octorpki	Affected: unspecified , < 1.3.0 (custom)

Date Public

2021-09-03 00:00

Credits

Job Snijders

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T17:09:08.491Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9"
          },
          {
            "name": "DSA-5041",
            "tags": [
              "vendor-advisory",
              "x_refsource_DEBIAN",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2022/dsa-5041"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "octorpki",
          "vendor": "Cloudflare",
          "versions": [
            {
              "lessThan": "1.3.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Job Snijders"
        }
      ],
      "datePublic": "2021-09-03T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Missing out of bounds check",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-01-12T10:06:26.000Z",
        "orgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
        "shortName": "cloudflare"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9"
        },
        {
          "name": "DSA-5041",
          "tags": [
            "vendor-advisory",
            "x_refsource_DEBIAN"
          ],
          "url": "https://www.debian.org/security/2022/dsa-5041"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to 1.3.0"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values",
      "x_generator": {
        "engine": "Vulnogram 0.0.9"
      },
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cna@cloudflare.com",
          "DATE_PUBLIC": "2021-09-03T16:28:00.000Z",
          "ID": "CVE-2021-3761",
          "STATE": "PUBLIC",
          "TITLE": "OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "octorpki",
                      "version": {
                        "version_data": [
                          {
                            "version_affected": "\u003c",
                            "version_value": "1.3.0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "Cloudflare"
              }
            ]
          }
        },
        "credit": [
          {
            "lang": "eng",
            "value": "Job Snijders"
          }
        ],
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues."
            }
          ]
        },
        "generator": {
          "engine": "Vulnogram 0.0.9"
        },
        "impact": {
          "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "Missing out of bounds check"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9",
              "refsource": "MISC",
              "url": "https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9"
            },
            {
              "name": "DSA-5041",
              "refsource": "DEBIAN",
              "url": "https://www.debian.org/security/2022/dsa-5041"
            }
          ]
        },
        "solution": [
          {
            "lang": "en",
            "value": "Upgrade to 1.3.0"
          }
        ],
        "source": {
          "discovery": "EXTERNAL"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
    "assignerShortName": "cloudflare",
    "cveId": "CVE-2021-3761",
    "datePublished": "2021-09-09T14:05:09.349Z",
    "dateReserved": "2021-09-01T00:00:00.000Z",
    "dateUpdated": "2024-09-17T02:56:31.062Z",
    "state": "PUBLISHED"
  },
  "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.

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.

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UBUNTU-CVE-2021-3761 (CVE-2021-3761)

CVE-2021-3761 (GCVE-0-2021-3761)

Tags

Sightings

Nomenclature

Related by attack behaviour