Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2024-03-06 11:08

Modified

2026-09-08 08:34

Summary

Anonymous user cache poisoning via development-mode header in Discourse

Details

Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "discourse",
        "purl": "pkg:bitnami/discourse"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.7.11"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-43794"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.",
  "id": "BIT-discourse-2021-43794",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2024-03-06T11:08:42.616Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hp"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-43794"
    }
  ],
  "schema_version": "1.5.0",
  "summary": "Anonymous user cache poisoning via development-mode header in Discourse"
}

CVE-2021-43794 (GCVE-0-2021-43794)

Vulnerability from cvelistv5 – Published: 2021-12-01 19:40 – Updated: 2024-08-04 04:03

Title

Anonymous user cache poisoning via development-mode header in Discourse

Summary

Severity

5.3 (Medium)


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

CWE

CWE-610 - Externally Controlled Reference to a Resource in Another Sphere

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7712 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/discourse/discourse/commit/2da…	x_refsource_MISC
https://github.com/discourse/discourse/security/a…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
discourse	discourse	Affected: stable < 2.7.11 Affected: beta < 2.8.0.beta9 Affected: tests-passed < 2.8.0.beta9

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T04:03:08.879Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hp"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "discourse",
          "vendor": "discourse",
          "versions": [
            {
              "status": "affected",
              "version": "stable \u003c 2.7.11"
            },
            {
              "status": "affected",
              "version": "beta \u003c 2.8.0.beta9"
            },
            {
              "status": "affected",
              "version": "tests-passed \u003c 2.8.0.beta9"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "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:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-610",
              "description": "CWE-610: Externally Controlled Reference to a Resource in Another Sphere",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-12-01T19:40:10.000Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hp"
        }
      ],
      "source": {
        "advisory": "GHSA-249g-pc77-65hp",
        "discovery": "UNKNOWN"
      },
      "title": "Anonymous user cache poisoning via development-mode header in Discourse",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-43794",
          "STATE": "PUBLIC",
          "TITLE": "Anonymous user cache poisoning via development-mode header in Discourse"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "discourse",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "stable \u003c 2.7.11"
                          },
                          {
                            "version_value": "beta \u003c 2.8.0.beta9"
                          },
                          {
                            "version_value": "tests-passed \u003c 2.8.0.beta9"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "discourse"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Discourse is an open source discussion platform. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown a JSON blob instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse."
            }
          ]
        },
        "impact": {
          "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "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:L",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-610: Externally Controlled Reference to a Resource in Another Sphere"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1",
              "refsource": "MISC",
              "url": "https://github.com/discourse/discourse/commit/2da0001965c6d8632d723c46ea5df9f22a1a23f1"
            },
            {
              "name": "https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hp",
              "refsource": "CONFIRM",
              "url": "https://github.com/discourse/discourse/security/advisories/GHSA-249g-pc77-65hp"
            }
          ]
        },
        "source": {
          "advisory": "GHSA-249g-pc77-65hp",
          "discovery": "UNKNOWN"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-43794",
    "datePublished": "2021-12-01T19:40:10.000Z",
    "dateReserved": "2021-11-16T00:00:00.000Z",
    "dateUpdated": "2024-08-04T04:03:08.879Z",
    "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.

Vulnerability timeline

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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

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