{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47507 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47507 is a medium-severity vulnerability in Linux kernel, published on 24 May 2024. 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-2021-47507 and fix it if it is affected.\n\nWhat it is: CVE-2021-47507 is a medium-severity vulnerability in Linux kernel, published on 24 May 2024. 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-2021-47507 in the wild and no public exploit code.\n\nAffected product: Linux kernel. 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-2021-47507/ (Markdown: https://insights.sbomify.com/CVE-2021-47507/index.md)","id":"CVE-2021-47507","markdown":"https://insights.sbomify.com/CVE-2021-47507/index.md","name":"CVE-2021-47507","record":{"aliases":["DEBIAN-CVE-2021-47507","UBUNTU-CVE-2021-47507"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel NFS","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel NFS daemon can cause a NULL pointer dereference and system crash during mount operations.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":4.7,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: Fix nsfd startup race (again)\n\nCommit bd5ae9288d64 (\"nfsd: register pernet ops last, unregister first\")\nhas re-opened rpc_pipefs_event() race against nfsd_net_id registration\n(register_pernet_subsys()) which has been fixed by commit bb7ffbf29e76\n(\"nfsd: fix nsfd startup race triggering BUG_ON\").\n\nRestore the order of register_pernet_subsys() vs register_cld_notifier().\nAdd WARN_ON() to prevent a future regression.\n\nCrash info:\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000012\nCPU: 8 PID: 345 Comm: mount Not tainted 5.4.144-... #1\npc : rpc_pipefs_event+0x54/0x120 [nfsd]\nlr : rpc_pipefs_event+0x48/0x120 [nfsd]\nCall trace:\n rpc_pipefs_event+0x54/0x120 [nfsd]\n blocking_notifier_call_chain\n rpc_fill_super\n get_tree_keyed\n rpc_fs_get_tree\n vfs_get_tree\n do_mount\n ksys_mount\n __arm64_sys_mount\n el0_svc_handler\n el0_svc","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":"nfsd: Fix nsfd startup race (again)","id":"CVE-2021-47507","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2021"},"n_packages":0,"n_references":4,"next":{"headline":"btrfs: free exchange changeset on failures","id":"CVE-2021-47508"},"packages":[],"prev":{"headline":"nfsd: fix use-after-free due to delegation race","id":"CVE-2021-47506"},"products":["Linux"],"published":"2024-05-24","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-23","vendors":["Linux"]},"summary":"A race condition in the Linux kernel NFS daemon can cause a NULL pointer dereference and system crash during mount operations.","url":"https://insights.sbomify.com/CVE-2021-47507/"}