{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-23993 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-23993 is a medium-severity denial of service vulnerability in Mozilla Thunderbird, published on 24 Jun 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-2021-23993 and fix it if it is affected.\n\nWhat it is: CVE-2021-23993 is a medium-severity denial of service vulnerability in Mozilla Thunderbird, published on 24 Jun 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-2021-23993 in the wild and no public exploit code.\n\nAffected product: Mozilla Thunderbird. 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-2021-23993/ (Markdown: https://insights.sbomify.com/CVE-2021-23993/index.md)","id":"CVE-2021-23993","markdown":"https://insights.sbomify.com/CVE-2021-23993/index.md","name":"CVE-2021-23993","record":{"aliases":["DEBIAN-CVE-2021-23993","GHSA-3pj2-rvj5-6646","UBUNTU-CVE-2021-23993"],"analysis":{"component_type":"desktop_application","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Thunderbird email client","requires_auth":"none","summary":"An attacker can cause denial of service in Thunderbird by crafting an OpenPGP key with an invalid self signature, preventing encrypted email sending.","user_interaction":"required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"thunderbird","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":[{"id":"CWE-347","name":"Improper Verification of Cryptographic Signature"}],"description":"An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird \u003c 78.9.1.","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":"Denial of service in Thunderbird","id":"CVE-2021-23993","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:thunderbird","products":["mozilla:thunderbird"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"Memory corruption in Firefox","id":"CVE-2021-23994"},"packages":[],"prev":{"headline":"Other in Thunderbird","id":"CVE-2021-23992"},"products":["Thunderbird"],"published":"2021-06-24","related":[{"cvss_score":9.8,"headline":"Ambiguous parsing of mail headers","id":"CVE-2026-92238","kev_date_added":null,"published":"2026-09-15"},{"cvss_score":9.8,"headline":"Calendar invitation attachments could launch local executables","id":"CVE-2026-84637","kev_date_added":null,"published":"2026-09-01"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2021-43529","kev_date_added":null,"published":"2023-02-16"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2019-11703","kev_date_added":null,"published":"2019-07-23"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2019-11704","kev_date_added":null,"published":"2019-07-23"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2019-11705","kev_date_added":null,"published":"2019-07-23"},{"cvss_score":9.8,"headline":"Use after free in Thunderbird","id":"CVE-2018-18512","kev_date_added":null,"published":"2019-04-26"}],"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":"2024-08-03","vendors":["Mozilla"]},"summary":"An attacker can cause denial of service in Thunderbird by crafting an OpenPGP key with an invalid self signature, preventing encrypted email sending.","url":"https://insights.sbomify.com/CVE-2021-23993/"}