CVE-2021-3838 (GCVE-0-2021-3838)

Vulnerability from cvelistv5 – Published: 2024-11-15 10:51 – Updated: 2024-11-18 14:41
VLAI
Title
PHAR Deserialization in dompdf/dompdf
Summary
DomPDF before version 2.0.0 is vulnerable to PHAR deserialization due to a lack of checking on the protocol before passing it into the file_get_contents() function. An attacker who can upload files of any type to the server can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution, especially when DOMPdf is used with frameworks with documented POP chains like Laravel or vulnerable developer code.
Severity
9.8 (Critical)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-11-18 14:40 UTC
CWE
  • CWE-502 - Deserialization of Untrusted Data
Assigner
@huntr_ai CNA under the mitre root
CNA scorecard C 65/100 over 37 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
dompdf dompdf/dompdf Affected: unspecified , < 2.0.0 (custom)
guessed Create a notification for this product.
dompdf dompdf Affected: 0 , < 2.0.0 (custom)
    cpe:2.3:a:dompdf:dompdf:*:beta3:*:*:*:*:*:*
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "affected": [
          {
            "cpes": [
              "cpe:2.3:a:dompdf:dompdf:*:beta3:*:*:*:*:*:*"
            ],
            "defaultStatus": "unknown",
            "product": "dompdf",
            "vendor": "dompdf",
            "versions": [
              {
                "lessThan": "2.0.0",
                "status": "affected",
                "version": "0",
                "versionType": "custom"
              }
            ]
          }
        ],
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-3838",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-11-18T14:40:28.381255Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-11-18T14:41:07.247Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "dompdf/dompdf",
          "vendor": "dompdf",
          "versions": [
            {
              "lessThan": "2.0.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "DomPDF before version 2.0.0 is vulnerable to PHAR deserialization due to a lack of checking on the protocol before passing it into the file_get_contents() function. An attacker who can upload files of any type to the server can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution, especially when DOMPdf is used with frameworks with documented POP chains like Laravel or vulnerable developer code."
        }
      ],
      "metrics": [
        {
          "cvssV3_0": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-502",
              "description": "CWE-502 Deserialization of Untrusted Data",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-11-15T10:57:26.565Z",
        "orgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
        "shortName": "@huntr_ai"
      },
      "references": [
        {
          "url": "https://huntr.com/bounties/0bdddc12-ff67-4815-ab9f-6011a974f48e"
        },
        {
          "url": "https://github.com/dompdf/dompdf/commit/99aeec1efec9213e87098d42eb09439e7ee0bb6a"
        }
      ],
      "source": {
        "advisory": "0bdddc12-ff67-4815-ab9f-6011a974f48e",
        "discovery": "EXTERNAL"
      },
      "title": "PHAR Deserialization in dompdf/dompdf"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
    "assignerShortName": "@huntr_ai",
    "cveId": "CVE-2021-3838",
    "datePublished": "2024-11-15T10:51:36.766Z",
    "dateReserved": "2021-09-29T00:25:46.565Z",
    "dateUpdated": "2024-11-18T14:41:07.247Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-3838",
      "date": "2026-11-11",
      "epss": "0.01432",
      "percentile": "0.73403"
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:dompdf_project:dompdf:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "CF3441FB-3B15-4935-8A8F-964D7DDFBCAD",
                    "versionEndExcluding": "2.0.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "DomPDF before version 2.0.0 is vulnerable to PHAR deserialization due to a lack of checking on the protocol before passing it into the file_get_contents() function. An attacker who can upload files of any type to the server can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution, especially when DOMPdf is used with frameworks with documented POP chains like Laravel or vulnerable developer code."
          },
          {
            "lang": "es",
            "value": "DomPDF anterior a la versi\u00f3n 2.0.0 es vulnerable a la deserializaci\u00f3n de PHAR debido a la falta de verificaci\u00f3n del protocolo antes de pasarlo a la funci\u00f3n file_get_contents(). Un atacante que pueda cargar archivos de cualquier tipo al servidor puede pasar el protocolo phar:// para deserializar el archivo cargado y crear instancias de objetos PHP arbitrarios. Esto puede provocar la ejecuci\u00f3n remota de c\u00f3digo, especialmente cuando DOMPdf se utiliza con marcos con cadenas POP documentadas como Laravel o c\u00f3digo de desarrollador vulnerable."
          }
        ],
        "id": "CVE-2021-3838",
        "lastModified": "2024-11-19T17:11:23.277",
        "metrics": {
          "cvssMetricV30": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.0"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.9,
              "source": "security@huntr.dev",
              "type": "Secondary"
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.9,
              "source": "nvd@nist.gov",
              "type": "Primary"
            },
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.9,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ]
        },
        "published": "2024-11-15T11:15:05.763",
        "references": [
          {
            "source": "security@huntr.dev",
            "tags": [
              "Patch"
            ],
            "url": "https://github.com/dompdf/dompdf/commit/99aeec1efec9213e87098d42eb09439e7ee0bb6a"
          },
          {
            "source": "security@huntr.dev",
            "tags": [
              "Exploit",
              "Issue Tracking",
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://huntr.com/bounties/0bdddc12-ff67-4815-ab9f-6011a974f48e"
          }
        ],
        "sourceIdentifier": "security@huntr.dev",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-502"
              }
            ],
            "source": "security@huntr.dev",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "current_release_date": "2025-05-29T03:21:21+00:00",
      "cve": "CVE-2021-3838",
      "id": "CVE-2021-3838",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "PHAR Deserialization in dompdf/dompdf",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-3838.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "affected": [
              {
                "cpes": [
                  "cpe:2.3:a:dompdf:dompdf:*:beta3:*:*:*:*:*:*"
                ],
                "defaultStatus": "unknown",
                "product": "dompdf",
                "vendor": "dompdf",
                "versions": [
                  {
                    "lessThan": "2.0.0",
                    "status": "affected",
                    "version": "0",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "HIGH",
                  "baseScore": 9.8,
                  "baseSeverity": "CRITICAL",
                  "confidentialityImpact": "HIGH",
                  "integrityImpact": "HIGH",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2021-3838",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2024-11-18T14:40:28.381255Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2024-11-18T14:40:16.545Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "dompdf/dompdf",
              "vendor": "dompdf",
              "versions": [
                {
                  "lessThan": "2.0.0",
                  "status": "affected",
                  "version": "unspecified",
                  "versionType": "custom"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "DomPDF before version 2.0.0 is vulnerable to PHAR deserialization due to a lack of checking on the protocol before passing it into the file_get_contents() function. An attacker who can upload files of any type to the server can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution, especially when DOMPdf is used with frameworks with documented POP chains like Laravel or vulnerable developer code."
            }
          ],
          "metrics": [
            {
              "cvssV3_0": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.0"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-502",
                  "description": "CWE-502 Deserialization of Untrusted Data",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2024-11-15T10:57:26.565Z",
            "orgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
            "shortName": "@huntr_ai"
          },
          "references": [
            {
              "url": "https://huntr.com/bounties/0bdddc12-ff67-4815-ab9f-6011a974f48e"
            },
            {
              "url": "https://github.com/dompdf/dompdf/commit/99aeec1efec9213e87098d42eb09439e7ee0bb6a"
            }
          ],
          "source": {
            "advisory": "0bdddc12-ff67-4815-ab9f-6011a974f48e",
            "discovery": "EXTERNAL"
          },
          "title": "PHAR Deserialization in dompdf/dompdf"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
        "assignerShortName": "@huntr_ai",
        "cveId": "CVE-2021-3838",
        "datePublished": "2024-11-15T10:51:36.766Z",
        "dateReserved": "2021-09-29T00:25:46.565Z",
        "dateUpdated": "2024-11-18T14:41:07.247Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    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.