FKIE_CVE-2025-66550

Vulnerability from fkie_nvd - Published: 2025-12-05 17:16 - Updated: 2025-12-10 14:13
Severity ?
5.7 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Summary
Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a calendar event with a crafted attachment that links to a download link of a file on the same Nextcloud server, the file would be downloaded without the user confirming the action. This vulnerability is fixed in 4.7.17 and 5.2.4.
References
security-advisories@github.comhttps://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769Patch
security-advisories@github.comhttps://github.com/nextcloud/calendar/pull/6971Issue Tracking
security-advisories@github.comhttps://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcvPatch, Vendor Advisory
security-advisories@github.comhttps://hackerone.com/reports/3112033Issue Tracking, Vendor Advisory
Impacted products
Vendor Product Version
nextcloud calendar *
nextcloud calendar *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "1B86471C-96D9-4152-BD53-8AC98B0C428D",
              "versionEndExcluding": "4.7.17",
              "versionStartIncluding": "4.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "833B51DE-8445-40F4-A4D4-E7B88F3C2B0C",
              "versionEndExcluding": "5.2.4",
              "versionStartIncluding": "5.0.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a calendar event with a crafted attachment that links to a download link of a file on the same Nextcloud server, the file would be downloaded without the user confirming the action. This vulnerability is fixed in 4.7.17 and 5.2.4."
    }
  ],
  "id": "CVE-2025-66550",
  "lastModified": "2025-12-10T14:13:30.870",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.1,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-12-05T17:16:05.500",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking"
      ],
      "url": "https://github.com/nextcloud/calendar/pull/6971"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "url": "https://hackerone.com/reports/3112033"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-241"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.