GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2019-9821 (GCVE-0-2019-9821)

Vulnerability from cvelistv5 – Published: 2019-07-23 13:23 – Updated: 2024-08-04 22:01
VLAI
Summary
A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox < 67.
CWE
  • Use-after-free in AssertWorkerThread
References
Impacted products
Vendor Product Version CPE status
Mozilla Firefox Affected: unspecified , < 67 (custom)
guessed Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T22:01:55.087Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.mozilla.org/security/advisories/mfsa2019-13/"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1539125"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Firefox",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThan": "67",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox \u003c 67."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Use-after-free in AssertWorkerThread",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2019-07-23T13:23:21.000Z",
        "orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
        "shortName": "mozilla"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.mozilla.org/security/advisories/mfsa2019-13/"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1539125"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security@mozilla.org",
          "ID": "CVE-2019-9821",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "Firefox",
                      "version": {
                        "version_data": [
                          {
                            "version_affected": "\u003c",
                            "version_value": "67"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "Mozilla"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox \u003c 67."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "Use-after-free in AssertWorkerThread"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://www.mozilla.org/security/advisories/mfsa2019-13/",
              "refsource": "MISC",
              "url": "https://www.mozilla.org/security/advisories/mfsa2019-13/"
            },
            {
              "name": "https://bugzilla.mozilla.org/show_bug.cgi?id=1539125",
              "refsource": "MISC",
              "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1539125"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
    "assignerShortName": "mozilla",
    "cveId": "CVE-2019-9821",
    "datePublished": "2019-07-23T13:23:21.000Z",
    "dateReserved": "2019-03-14T00:00:00.000Z",
    "dateUpdated": "2024-08-04T22:01:55.087Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2019-9821",
      "date": "2026-09-16",
      "epss": "0.0085",
      "percentile": "0.56375"
    },
    "fkie_nvd": {
      "configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*\", \"versionEndExcluding\": \"67.0\", \"matchCriteriaId\": \"83DEE955-3E09-489F-BE40-2FD33EACF436\"}]}]}]",
      "descriptions": "[{\"lang\": \"en\", \"value\": \"A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox \u003c 67.\"}, {\"lang\": \"es\", \"value\": \"Puede ocurrir una vulnerabilidad de uso de la memoria previamente liberada en AssertWorkerThread debido a una condici\\u00f3n de carrera con trabajadores compartidos. Esto resulta en un bloqueo potencialmente explotable. Esta vulnerabilidad afecta a Firefox anterior a versi\\u00f3n 67.\"}]",
      "id": "CVE-2019-9821",
      "lastModified": "2024-11-21T04:52:22.667",
      "metrics": "{\"cvssMetricV30\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.0\", \"vectorString\": \"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H\", \"baseScore\": 8.1, \"baseSeverity\": \"HIGH\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"HIGH\", \"integrityImpact\": \"HIGH\", \"availabilityImpact\": \"HIGH\"}, \"exploitabilityScore\": 2.2, \"impactScore\": 5.9}], \"cvssMetricV2\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"2.0\", \"vectorString\": \"AV:N/AC:M/Au:N/C:P/I:P/A:P\", \"baseScore\": 6.8, \"accessVector\": \"NETWORK\", \"accessComplexity\": \"MEDIUM\", \"authentication\": \"NONE\", \"confidentialityImpact\": \"PARTIAL\", \"integrityImpact\": \"PARTIAL\", \"availabilityImpact\": \"PARTIAL\"}, \"baseSeverity\": \"MEDIUM\", \"exploitabilityScore\": 8.6, \"impactScore\": 6.4, \"acInsufInfo\": false, \"obtainAllPrivilege\": false, \"obtainUserPrivilege\": false, \"obtainOtherPrivilege\": false, \"userInteractionRequired\": false}]}",
      "published": "2019-07-23T14:15:17.483",
      "references": "[{\"url\": \"https://bugzilla.mozilla.org/show_bug.cgi?id=1539125\", \"source\": \"security@mozilla.org\", \"tags\": [\"Permissions Required\", \"Vendor Advisory\"]}, {\"url\": \"https://www.mozilla.org/security/advisories/mfsa2019-13/\", \"source\": \"security@mozilla.org\", \"tags\": [\"Vendor Advisory\"]}, {\"url\": \"https://bugzilla.mozilla.org/show_bug.cgi?id=1539125\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Permissions Required\", \"Vendor Advisory\"]}, {\"url\": \"https://www.mozilla.org/security/advisories/mfsa2019-13/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Vendor Advisory\"]}]",
      "sourceIdentifier": "security@mozilla.org",
      "vulnStatus": "Modified",
      "weaknesses": "[{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-362\"}, {\"lang\": \"en\", \"value\": \"CWE-416\"}]}]"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2019-9821\",\"sourceIdentifier\":\"security@mozilla.org\",\"published\":\"2019-07-23T14:15:17.483\",\"lastModified\":\"2024-11-21T04:52:22.667\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox \u003c 67.\"},{\"lang\":\"es\",\"value\":\"Puede ocurrir una vulnerabilidad de uso de la memoria previamente liberada en AssertWorkerThread debido a una condici\u00f3n de carrera con trabajadores compartidos. Esto resulta en un bloqueo potencialmente explotable. Esta vulnerabilidad afecta a Firefox anterior a versi\u00f3n 67.\"}],\"metrics\":{\"cvssMetricV30\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.0\",\"vectorString\":\"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.2,\"impactScore\":5.9}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:M/Au:N/C:P/I:P/A:P\",\"baseScore\":6.8,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"MEDIUM\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"PARTIAL\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"PARTIAL\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":8.6,\"impactScore\":6.4,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-362\"},{\"lang\":\"en\",\"value\":\"CWE-416\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"67.0\",\"matchCriteriaId\":\"83DEE955-3E09-489F-BE40-2FD33EACF436\"}]}]}],\"references\":[{\"url\":\"https://bugzilla.mozilla.org/show_bug.cgi?id=1539125\",\"source\":\"security@mozilla.org\",\"tags\":[\"Permissions Required\",\"Vendor Advisory\"]},{\"url\":\"https://www.mozilla.org/security/advisories/mfsa2019-13/\",\"source\":\"security@mozilla.org\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://bugzilla.mozilla.org/show_bug.cgi?id=1539125\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Permissions Required\",\"Vendor Advisory\"]},{\"url\":\"https://www.mozilla.org/security/advisories/mfsa2019-13/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Vendor Advisory\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2025-11-21T16:20:54+00:00",
      "cve": "CVE-2019-9821",
      "id": "CVE-2019-9821",
      "initial_release_date": "2019-05-21T00:00:00+00:00",
      "product_status:known_not_affected": "7",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "firefox: use-after-free in AssertWorkerThread leading to crash",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2019/cve-2019-9821.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-09-03T00:54:33Z",
      "cve": "CVE-2019-9821",
      "id": "CVE-2019-9821",
      "initial_release_date": "2023-02-15T04:14:06Z",
      "product_status:known_affected": "24",
      "product_status:known_not_affected": "8",
      "product_status:recommended": "15",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2019-9821",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2019-9821.json",
      "version": "17"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

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.


Loading…