{"answers":{"affected":"It affects 4 products.","exploited":"There is no known exploitation of CVE-2021-43535 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-43535 is a high-severity use after free vulnerability in Debian Debian Linux, 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-2021-43535 and fix it if it is affected.\n\nWhat it is: CVE-2021-43535 is a high-severity use after free vulnerability in Debian Debian Linux, 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-2021-43535 in the wild and no public exploit code.\n\nAffected product: Debian Debian Linux. 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-2021-43535/ (Markdown: https://insights.sbomify.com/CVE-2021-43535/index.md)","id":"CVE-2021-43535","markdown":"https://insights.sbomify.com/CVE-2021-43535/index.md","name":"CVE-2021-43535","record":{"aliases":["DEBIAN-CVE-2021-43535","GHSA-9c2c-v6c7-rjgv","UBUNTU-CVE-2021-43535"],"analysis":{"component_type":"browser","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Mozilla Firefox","requires_auth":"none","summary":"A use-after-free in HTTP2 session handling allows attackers to cause memory corruption, leading to crashes or potential code execution in Firefox and Thunderbird.","user_interaction":"required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"firefox","vendor":"mozilla"},{"product":"firefox_esr","vendor":"mozilla"},{"product":"thunderbird","vendor":"mozilla"}],"cvss":{"score":8.8,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox \u003c 93, Thunderbird \u003c 91.3, and Firefox ESR \u003c 91.3.","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":"Use after free in Firefox","id":"CVE-2021-43535","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"debian:debian_linux","products":["debian:debian_linux","mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"type":"use_after_free","year":"2021"},"n_packages":0,"n_references":8,"next":{"headline":"Information disclosure in Firefox","id":"CVE-2021-43536"},"packages":[],"prev":{"headline":"Memory corruption in Firefox","id":"CVE-2021-43534"},"products":["Firefox","Firefox ESR","Thunderbird"],"published":"2021-12-08","related":[{"cvss_score":10,"headline":"ProFTPD Improper Access Control","id":"CVE-2015-3306","kev_date_added":"2026-10-08","published":"2015-05-18"},{"cvss_score":9.9,"headline":"RoundCube Webmail Deserialization of Untrusted Data","id":"CVE-2025-49113","kev_date_added":"2026-02-20","published":"2025-06-02"},{"cvss_score":9.8,"headline":"GNU InetUtils Argument Injection","id":"CVE-2026-24061","kev_date_added":"2026-01-26","published":"2026-01-21"},{"cvss_score":9.8,"headline":"Linux Kernel Improper Check for Unusual or Exceptional Conditions","id":"CVE-2025-39682","kev_date_added":"2026-09-18","published":"2025-09-05"},{"cvss_score":9.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2024-9680","kev_date_added":"2024-10-15","published":"2024-10-09"},{"cvss_score":9.8,"headline":"RARLAB UnRAR Directory Traversal","id":"CVE-2022-30333","kev_date_added":"2022-08-09","published":"2022-05-09"},{"cvss_score":9.8,"headline":"Roundcube Webmail SQL Injection","id":"CVE-2021-44026","kev_date_added":"2023-06-22","published":"2021-11-19"}],"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":"CWE Terms of Use","name":"CWE (MITRE)"},{"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":"A use-after-free in HTTP2 session handling allows attackers to cause memory corruption, leading to crashes or potential code execution in Firefox and Thunderbird.","url":"https://insights.sbomify.com/CVE-2021-43535/"}