CVE-2021-42567 (GCVE-0-2021-42567)

Vulnerability from cvelistv5 – Published: 2021-12-07 21:10 – Updated: 2024-08-04 03:38
VLAI Shadowserver KEVIntel
Summary
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE
  • n/a
Assigner
References
Shadowserver
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 9a8ff6ac-2bd6-4101-9d73-faaec11a9cec

Vulnerability ID: CVE-2021-42567

Status: Confirmed

Status Updated: 2025-12-09 00:00 UTC

Exploited: Yes

Characteristics
Severity: 61.0
Timestamps
First Seen: 2023-10-23
Asserted: 2023-10-23
Last Seen: 2025-12-09
Scope
Asset Exposure: ['internet-facing']
Notes: Affected: Apereo / CAS | Class: other-software | Severity: Medium (CVSS 6.1) | IoT: no | In CISA KEV: no | Honeypot connections on 2025-12-09: 2
Evidence

Type: Honeypot

Signal: In The Wild Attempts

Confidence: 70%

Source: shadowserver

Details
1D 2
Iot no
Feed Shadowserver Foundation honeypot/exploited-vulnerabilities
Type http-scan
Class other-software
7D Avg 0
Vendor Apereo
30D Avg 0
90D Avg 0
Product CAS
Cisa Kev no
Connections 2
Observation Date 2025-12-09
Vulnerability Class CVSS
Vulnerability Score 6.1
Vulnerability Severity Medium
References
Created: 2026-06-30 09:23 UTC | Updated: 2026-06-30 10:20 UTC
KEVIntel
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: eae655b5-2c55-4e5f-99ab-e955bb992c33

Vulnerability ID: CVE-2021-42567

Status: Confirmed

Status Updated: 2021-12-07 21:10 UTC

Exploited: Yes

Timestamps
First Seen: 2021-12-07
Asserted: 2021-12-07
Scope
Notes: KEVIntel entry: Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints. | Affected: n/a / n/a | Used in malware: unknown | Not yet in CISA KEV: True
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: kevintel

Details
Feed KEVIntel (kevintel.com)
Title Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
Vendor n/a
Product n/a
Added Date 2021-12-07T21:10:49.000Z
Cvss Score None
Epss Score None
Cvss Severity None
Epss Percentile None
Used In Malware unknown
Ahead Of Cisa Kev None
Not Yet In Cisa Kev True
References
Created: 2026-06-23 14:06 UTC | Updated: 2026-06-23 14:06 UTC
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T03:38:49.276Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/apereo/cas/releases"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://apereo.github.io/2021/10/18/restvuln/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-12-07T21:10:49.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/apereo/cas/releases"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://apereo.github.io/2021/10/18/restvuln/"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-42567",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/apereo/cas/releases",
              "refsource": "MISC",
              "url": "https://github.com/apereo/cas/releases"
            },
            {
              "name": "https://apereo.github.io/2021/10/18/restvuln/",
              "refsource": "CONFIRM",
              "url": "https://apereo.github.io/2021/10/18/restvuln/"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-42567",
    "datePublished": "2021-12-07T21:10:49.000Z",
    "dateReserved": "2021-10-18T00:00:00.000Z",
    "dateUpdated": "2024-08-04T03:38:49.276Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-42567",
      "date": "2026-06-29",
      "epss": "0.08064",
      "percentile": "0.94075"
    },
    "fkie_nvd": {
      "configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:apereo:central_authentication_service:*:*:*:*:*:*:*:*\", \"versionStartIncluding\": \"6.3.0\", \"versionEndExcluding\": \"6.3.7.1\", \"matchCriteriaId\": \"1E0AE631-B3F1-4F01-B70A-F1099DB4C976\"}, {\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:apereo:central_authentication_service:*:*:*:*:*:*:*:*\", \"versionStartIncluding\": \"6.4.0\", \"versionEndExcluding\": \"6.4.2\", \"matchCriteriaId\": \"29A88276-77E2-4EF9-8823-42E02AF0E1E3\"}]}]}]",
      "descriptions": "[{\"lang\": \"en\", \"value\": \"Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.\"}, {\"lang\": \"es\", \"value\": \"Apereo CAS versiones hasta 6.4.1, permite un ataque de tipo XSS por medio de peticiones POST enviadas a los endpoints de la API REST\"}]",
      "id": "CVE-2021-42567",
      "lastModified": "2024-11-21T06:27:49.843",
      "metrics": "{\"cvssMetricV31\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N\", \"baseScore\": 6.1, \"baseSeverity\": \"MEDIUM\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"REQUIRED\", \"scope\": \"CHANGED\", \"confidentialityImpact\": \"LOW\", \"integrityImpact\": \"LOW\", \"availabilityImpact\": \"NONE\"}, \"exploitabilityScore\": 2.8, \"impactScore\": 2.7}], \"cvssMetricV2\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"2.0\", \"vectorString\": \"AV:N/AC:M/Au:N/C:N/I:P/A:N\", \"baseScore\": 4.3, \"accessVector\": \"NETWORK\", \"accessComplexity\": \"MEDIUM\", \"authentication\": \"NONE\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"PARTIAL\", \"availabilityImpact\": \"NONE\"}, \"baseSeverity\": \"MEDIUM\", \"exploitabilityScore\": 8.6, \"impactScore\": 2.9, \"acInsufInfo\": false, \"obtainAllPrivilege\": false, \"obtainUserPrivilege\": false, \"obtainOtherPrivilege\": false, \"userInteractionRequired\": true}]}",
      "published": "2021-12-07T22:15:06.907",
      "references": "[{\"url\": \"https://apereo.github.io/2021/10/18/restvuln/\", \"source\": \"cve@mitre.org\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/apereo/cas/releases\", \"source\": \"cve@mitre.org\", \"tags\": [\"Release Notes\", \"Third Party Advisory\"]}, {\"url\": \"https://apereo.github.io/2021/10/18/restvuln/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/apereo/cas/releases\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Release Notes\", \"Third Party Advisory\"]}]",
      "sourceIdentifier": "cve@mitre.org",
      "vulnStatus": "Modified",
      "weaknesses": "[{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-79\"}]}]"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-42567\",\"sourceIdentifier\":\"cve@mitre.org\",\"published\":\"2021-12-07T22:15:06.907\",\"lastModified\":\"2026-06-17T04:09:50.740\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.\"},{\"lang\":\"es\",\"value\":\"Apereo CAS versiones hasta 6.4.1, permite un ataque de tipo XSS por medio de peticiones POST enviadas a los endpoints de la API REST\"}],\"affected\":[{\"source\":\"cve@mitre.org\",\"affectedData\":[{\"vendor\":\"n/a\",\"product\":\"n/a\",\"versions\":[{\"version\":\"n/a\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N\",\"baseScore\":6.1,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":2.7}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:M/Au:N/C:N/I:P/A:N\",\"baseScore\":4.3,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"MEDIUM\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"NONE\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":8.6,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":true}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apereo:central_authentication_service:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.3.0\",\"versionEndExcluding\":\"6.3.7.1\",\"matchCriteriaId\":\"1E0AE631-B3F1-4F01-B70A-F1099DB4C976\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apereo:central_authentication_service:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.4.0\",\"versionEndExcluding\":\"6.4.2\",\"matchCriteriaId\":\"29A88276-77E2-4EF9-8823-42E02AF0E1E3\"}]}]}],\"references\":[{\"url\":\"https://apereo.github.io/2021/10/18/restvuln/\",\"source\":\"cve@mitre.org\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/apereo/cas/releases\",\"source\":\"cve@mitre.org\",\"tags\":[\"Release Notes\",\"Third Party Advisory\"]},{\"url\":\"https://apereo.github.io/2021/10/18/restvuln/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/apereo/cas/releases\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Release Notes\",\"Third Party Advisory\"]}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.