{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47129 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47129 is a high-severity vulnerability in Linux kernel, published on 15 Mar 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-2021-47129 and fix it if it is affected.\n\nWhat it is: CVE-2021-47129 is a high-severity vulnerability in Linux kernel, published on 15 Mar 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-2021-47129 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-2021-47129/ (Markdown: https://insights.sbomify.com/CVE-2021-47129/index.md)","id":"CVE-2021-47129","markdown":"https://insights.sbomify.com/CVE-2021-47129/index.md","name":"CVE-2021-47129","record":{"aliases":["DEBIAN-CVE-2021-47129","GHSA-w7x4-qp38-gw56","UBUNTU-CVE-2021-47129"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel netfilter","requires_auth":"low_privilege","summary":"A logic error in the Linux kernel netfilter module causes a kernel warning and potential crash when processing confirmed conntrack entries.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-273","name":"Improper Check for Dropped Privileges"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_ct: skip expectations for confirmed conntrack\n\nnft_ct_expect_obj_eval() calls nf_ct_ext_add() for a confirmed\nconntrack entry. However, nf_ct_ext_add() can only be called for\n!nf_ct_is_confirmed().\n\n[ 1825.349056] WARNING: CPU: 0 PID: 1279 at net/netfilter/nf_conntrack_extend.c:48 nf_ct_xt_add+0x18e/0x1a0 [nf_conntrack]\n[ 1825.351391] RIP: 0010:nf_ct_ext_add+0x18e/0x1a0 [nf_conntrack]\n[ 1825.351493] Code: 41 5c 41 5d 41 5e 41 5f c3 41 bc 0a 00 00 00 e9 15 ff ff ff ba 09 00 00 00 31 f6 4c 89 ff e8 69 6c 3d e9 eb 96 45 31 ed eb cd \u003c0f\u003e 0b e9 b1 fe ff ff e8 86 79 14 e9 eb bf 0f 1f 40 00 0f 1f 44 00\n[ 1825.351721] RSP: 0018:ffffc90002e1f1e8 EFLAGS: 00010202\n[ 1825.351790] RAX: 000000000000000e RBX: ffff88814f5783c0 RCX: ffffffffc0e4f887\n[ 1825.351881] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88814f578440\n[ 1825.351971] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88814f578447\n[ 1825.352060] R10: ffffed1029eaf088 R11: 0000000000000001 R12: ffff88814f578440\n[ 1825.352150] R13: ffff8882053f3a00 R14: 0000000000000000 R15: 0000000000000a20\n[ 1825.352240] FS:  00007f992261c900(0000) GS:ffff889faec00000(0000) knlGS:0000000000000000\n[ 1825.352343] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 1825.352417] CR2: 000056070a4d1158 CR3: 000000015efe0000 CR4: 0000000000350ee0\n[ 1825.352508] Call Trace:\n[ 1825.352544]  nf_ct_helper_ext_add+0x10/0x60 [nf_conntrack]\n[ 1825.352641]  nft_ct_expect_obj_eval+0x1b8/0x1e0 [nft_ct]\n[ 1825.352716]  nft_do_chain+0x232/0x850 [nf_tables]\n\nAdd the ct helper extension only for unconfirmed conntrack. Skip rule\nevaluation if the ct helper extension does not exist. Thus, you can\nonly create expectations from the first packet.\n\nIt should be possible to remove this limitation by adding a new action\nto attach a generic ct helper to the first packet. Then, use this ct\nhelper extension from follow up packets to create the ct expectation.\n\nWhile at it, add a missing check to skip the template conntrack too\nand remove check for IPCT_UNTRACK which is implicit to !ct.","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":"netfilter: nft_ct: skip expectations for confirmed conntrack","id":"CVE-2021-47129","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2021"},"n_packages":0,"n_references":4,"next":{"headline":"nvmet: fix freeing unallocated p2pmem","id":"CVE-2021-47130"},"packages":[],"prev":{"headline":"bpf, lockdown, audit: Fix buggy SELinux lockdown permission checks","id":"CVE-2021-47128"},"products":["Linux"],"published":"2024-03-15","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":"2026-08-05","vendors":["Linux"]},"summary":"A logic error in the Linux kernel netfilter module causes a kernel warning and potential crash when processing confirmed conntrack entries.","url":"https://insights.sbomify.com/CVE-2021-47129/"}