{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-43540 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-43540 is a medium-severity missing authorization vulnerability in Mozilla Firefox, published on 8 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2021-43540 and fix it if it is affected.\n\nWhat it is: CVE-2021-43540 is a medium-severity missing authorization vulnerability in Mozilla Firefox, published on 8 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2021-43540 in the wild and no public exploit code.\n\nAffected product: Mozilla Firefox. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-43540/ (Markdown: https://insights.sbomify.com/CVE-2021-43540/index.md)","id":"CVE-2021-43540","markdown":"https://insights.sbomify.com/CVE-2021-43540/index.md","name":"CVE-2021-43540","record":{"aliases":["GHSA-vj37-39rq-5f3g","UBUNTU-CVE-2021-43540"],"analysis":{"component_type":"browser","fix_type":"upgrade","impacts":["privilege_escalation","data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Firefox browser","requires_auth":"none","summary":"WebExtensions could install persistent ServiceWorkers on third-party sites, allowing unauthorized data access or persistence beyond extension removal.","user_interaction":"required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"firefox","vendor":"mozilla"}],"cvss":{"score":6.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","version":"3.1"},"cwes":[],"description":"WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox \u003c 95.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Missing authorization in Firefox","id":"CVE-2021-43540","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:firefox","products":["mozilla:firefox"],"type":"missing_authorization","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"Other in Firefox","id":"CVE-2021-43541"},"packages":[],"prev":{"headline":"Use after free in Firefox","id":"CVE-2021-43539"},"products":["Firefox"],"published":"2021-12-08","related":[{"cvss_score":10,"headline":"Mozilla Firefox and Thunderbird Sandbox Escape","id":"CVE-2019-11708","kev_date_added":"2022-05-23","published":"2019-07-23"},{"cvss_score":9.8,"headline":"Mozilla Multiple Products Remote Code Execution","id":"CVE-2010-3765","kev_date_added":"2025-10-06","published":"2010-10-27"},{"cvss_score":9.6,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2022-26486","kev_date_added":"2022-03-07","published":"2022-12-22"},{"cvss_score":8.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2022-26485","kev_date_added":"2022-03-07","published":"2022-12-22"},{"cvss_score":8.8,"headline":"Mozilla Firefox and Thunderbird Type Confusion","id":"CVE-2019-11707","kev_date_added":"2022-05-23","published":"2019-07-23"},{"cvss_score":8.1,"headline":"Mozilla Firefox And Thunderbird Use-After-Free","id":"CVE-2020-6819","kev_date_added":"2021-11-03","published":"2020-04-24"},{"cvss_score":8.1,"headline":"Mozilla Firefox And Thunderbird Use-After-Free","id":"CVE-2020-6820","kev_date_added":"2021-11-03","published":"2020-04-24"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-04","vendors":["Mozilla"]},"summary":"WebExtensions could install persistent ServiceWorkers on third-party sites, allowing unauthorized data access or persistence beyond extension removal.","url":"https://insights.sbomify.com/CVE-2021-43540/"}