{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47107 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47107 is a critical vulnerability in Linux kernel, published on 4 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47107 and fix it if it is affected.\n\nWhat it is: CVE-2021-47107 is a critical vulnerability in Linux kernel, published on 4 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47107 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-2021-47107/ (Markdown: https://insights.sbomify.com/CVE-2021-47107/index.md)","id":"CVE-2021-47107","markdown":"https://insights.sbomify.com/CVE-2021-47107/index.md","name":"CVE-2021-47107","record":{"aliases":["DEBIAN-CVE-2021-47107","GHSA-2mfm-m7q3-xch8","UBUNTU-CVE-2021-47107"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel NFSD","requires_auth":"none","summary":"A buffer overflow in the Linux kernel NFSD READDIR handler allows attackers to write beyond buffer boundaries, potentially causing crashes or code execution.","user_interaction":"not_required","vuln_class":"integer_overflow"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-120","name":"Buffer Copy without Checking Size of Input"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Fix READDIR buffer overflow\n\nIf a client sends a READDIR count argument that is too small (say,\nzero), then the buffer size calculation in the new init_dirlist\nhelper functions results in an underflow, allowing the XDR stream\nfunctions to write beyond the actual buffer.\n\nThis calculation has always been suspect. NFSD has never sanity-\nchecked the READDIR count argument, but the old entry encoders\nmanaged the problem correctly.\n\nWith the commits below, entry encoding changed, exposing the\nunderflow to the pointer arithmetic in xdr_reserve_space().\n\nModern NFS clients attempt to retrieve as much data as possible\nfor each READDIR request. Also, we have no unit tests that\nexercise the behavior of READDIR at the lower bound of @count\nvalues. Thus this case was missed during testing.","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 READDIR buffer overflow","id":"CVE-2021-47107","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"integer_overflow","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"drm/mediatek: hdmi: Perform NULL pointer check for mtk_hdmi_conf","id":"CVE-2021-47108"},"packages":[],"prev":{"headline":"netfilter: nf_tables: fix use-after-free in nft_set_catchall_destroy()","id":"CVE-2021-47106"},"products":["Linux"],"published":"2024-03-04","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":"2026-10-14","vendors":["Linux"]},"summary":"A buffer overflow in the Linux kernel NFSD READDIR handler allows attackers to write beyond buffer boundaries, potentially causing crashes or code execution.","url":"https://insights.sbomify.com/CVE-2021-47107/"}