{"answers":{"affected":"It affects 2 products.","exploited":"There is no known exploitation of CVE-2021-31924 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-31924 is a medium-severity authentication bypass vulnerability in Fedoraproject Fedora, published on 25 May 2021. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-31924 and fix it if it is affected.\n\nWhat it is: CVE-2021-31924 is a medium-severity authentication bypass vulnerability in Fedoraproject Fedora, published on 25 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-31924 in the wild and no public exploit code.\n\nAffected product: Fedoraproject Fedora. 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-2021-31924/ (Markdown: https://insights.sbomify.com/CVE-2021-31924/index.md)","id":"CVE-2021-31924","markdown":"https://insights.sbomify.com/CVE-2021-31924/index.md","name":"CVE-2021-31924","record":{"aliases":["DEBIAN-CVE-2021-31924","GHSA-v2qj-ch59-r5g4"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"PAM U2F library","requires_auth":"none","summary":"Local attackers can bypass PIN authentication in Yubico pam-u2f if configured to require PIN and the application allows NULL input, though physical key possession is still required.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"fedora","vendor":"fedoraproject"},{"product":"pam-u2f","vendor":"yubico"}],"cvss":{"score":6.8,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-287","name":"Improper Authentication"}],"description":"Yubico pam-u2f before 1.1.1 has a logic issue that, depending on the pam-u2f configuration and the application used, could lead to a local PIN bypass. This issue does not allow user presence (touch) or cryptographic signature verification to be bypassed, so an attacker would still need to physically possess and interact with the YubiKey or another enrolled authenticator. If pam-u2f is configured to require PIN authentication, and the application using pam-u2f allows the user to submit NULL as the PIN, pam-u2f will attempt to perform a FIDO2 authentication without PIN. If this authentication is successful, the PIN requirement is bypassed.","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":"Auth bypass in n/a","id":"CVE-2021-31924","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"fedoraproject:fedora","products":["fedoraproject:fedora"],"type":"auth_bypass","year":"2021"},"n_packages":0,"n_references":5,"next":{"headline":"Denial of service in n/a","id":"CVE-2021-31925"},"packages":[],"prev":{"headline":"Other in PingAccess","id":"CVE-2021-31923"},"products":["n/a"],"published":"2021-05-25","related":[{"cvss_score":9.8,"headline":"PHP-CGI OS Command Injection","id":"CVE-2024-4577","kev_date_added":"2024-06-12","published":"2024-06-09"},{"cvss_score":9.8,"headline":"Grafana Authentication Bypass","id":"CVE-2021-39226","kev_date_added":"2022-08-25","published":"2021-10-05"},{"cvss_score":9.8,"headline":"VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow","id":"CVE-2019-5544","kev_date_added":"2021-11-03","published":"2019-12-06"},{"cvss_score":9.6,"headline":"Google Chromium V8 Type Confusion","id":"CVE-2024-4947","kev_date_added":"2024-05-20","published":"2024-05-15"},{"cvss_score":9.6,"headline":"Google Chromium Visuals Use-After-Free","id":"CVE-2024-4671","kev_date_added":"2024-05-13","published":"2024-05-09"},{"cvss_score":9.6,"headline":"Google Chromium Mojo Insufficient Data Validation","id":"CVE-2022-3075","kev_date_added":"2022-09-08","published":"2022-09-26"},{"cvss_score":9.6,"headline":"Google Chromium Indexed DB API Use-After-Free","id":"CVE-2021-30633","kev_date_added":"2021-11-03","published":"2021-10-08"}],"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":["n/a"]},"summary":"Local attackers can bypass PIN authentication in Yubico pam-u2f if configured to require PIN and the application allows NULL input, though physical key possession is still required.","url":"https://insights.sbomify.com/CVE-2021-31924/"}