{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47106 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47106 is a high-severity use after free vulnerability in Linux kernel, published on 4 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-2021-47106 and fix it if it is affected.\n\nWhat it is: CVE-2021-47106 is a high-severity use after free vulnerability in Linux kernel, published on 4 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-2021-47106 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-2021-47106/ (Markdown: https://insights.sbomify.com/CVE-2021-47106/index.md)","id":"CVE-2021-47106","markdown":"https://insights.sbomify.com/CVE-2021-47106/index.md","name":"CVE-2021-47106","record":{"aliases":["DEBIAN-CVE-2021-47106","GHSA-gmwj-428v-53wv","UBUNTU-CVE-2021-47106"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the Linux kernel's netfilter subsystem allows local attackers to potentially execute arbitrary code or escalate privileges.","user_interaction":"not_required","vuln_class":"use_after_free"},"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-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: fix use-after-free in nft_set_catchall_destroy()\n\nWe need to use list_for_each_entry_safe() iterator\nbecause we can not access @catchall after kfree_rcu() call.\n\nsyzbot reported:\n\nBUG: KASAN: use-after-free in nft_set_catchall_destroy net/netfilter/nf_tables_api.c:4486 [inline]\nBUG: KASAN: use-after-free in nft_set_destroy net/netfilter/nf_tables_api.c:4504 [inline]\nBUG: KASAN: use-after-free in nft_set_destroy+0x3fd/0x4f0 net/netfilter/nf_tables_api.c:4493\nRead of size 8 at addr ffff8880716e5b80 by task syz-executor.3/8871\n\nCPU: 1 PID: 8871 Comm: syz-executor.3 Not tainted 5.16.0-rc5-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247\n __kasan_report mm/kasan/report.c:433 [inline]\n kasan_report.cold+0x83/0xdf mm/kasan/report.c:450\n nft_set_catchall_destroy net/netfilter/nf_tables_api.c:4486 [inline]\n nft_set_destroy net/netfilter/nf_tables_api.c:4504 [inline]\n nft_set_destroy+0x3fd/0x4f0 net/netfilter/nf_tables_api.c:4493\n __nft_release_table+0x79f/0xcd0 net/netfilter/nf_tables_api.c:9626\n nft_rcv_nl_event+0x4f8/0x670 net/netfilter/nf_tables_api.c:9688\n notifier_call_chain+0xb5/0x200 kernel/notifier.c:83\n blocking_notifier_call_chain kernel/notifier.c:318 [inline]\n blocking_notifier_call_chain+0x67/0x90 kernel/notifier.c:306\n netlink_release+0xcb6/0x1dd0 net/netlink/af_netlink.c:788\n __sock_release+0xcd/0x280 net/socket.c:649\n sock_close+0x18/0x20 net/socket.c:1314\n __fput+0x286/0x9f0 fs/file_table.c:280\n task_work_run+0xdd/0x1a0 kernel/task_work.c:164\n tracehook_notify_resume include/linux/tracehook.h:189 [inline]\n exit_to_user_mode_loop kernel/entry/common.c:175 [inline]\n exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207\n __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]\n syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300\n do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86\n entry_SYSCALL_64_after_hwframe+0x44/0xae\nRIP: 0033:0x7f75fbf28adb\nCode: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 \u003c48\u003e 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44\nRSP: 002b:00007ffd8da7ec10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003\nRAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f75fbf28adb\nRDX: 00007f75fc08e828 RSI: ffffffffffffffff RDI: 0000000000000003\nRBP: 00007f75fc08a960 R08: 0000000000000000 R09: 00007f75fc08e830\nR10: 00007ffd8da7ed10 R11: 0000000000000293 R12: 00000000002067c3\nR13: 00007ffd8da7ed10 R14: 00007f75fc088f60 R15: 0000000000000032\n \u003c/TASK\u003e\n\nAllocated by task 8886:\n kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38\n kasan_set_track mm/kasan/common.c:46 [inline]\n set_alloc_info mm/kasan/common.c:434 [inline]\n ____kasan_kmalloc mm/kasan/common.c:513 [inline]\n ____kasan_kmalloc mm/kasan/common.c:472 [inline]\n __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522\n kasan_kmalloc include/linux/kasan.h:269 [inline]\n kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3575\n kmalloc include/linux/slab.h:590 [inline]\n nft_setelem_catchall_insert net/netfilter/nf_tables_api.c:5544 [inline]\n nft_setelem_insert net/netfilter/nf_tables_api.c:5562 [inline]\n nft_add_set_elem+0x232e/0x2f40 net/netfilter/nf_tables_api.c:5936\n nf_tables_newsetelem+0x6ff/0xbb0 net/netfilter/nf_tables_api.c:6032\n nfnetlink_rcv_batch+0x1710/0x25f0 net/netfilter/nfnetlink.c:513\n nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]\n nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:652\n netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]\n netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345\n netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921\n sock_sendmsg_nosec net/\n---truncated---","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: nf_tables: fix use-after-free in nft_set_catchall_destroy()","id":"CVE-2021-47106","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"NFSD: Fix READDIR buffer overflow","id":"CVE-2021-47107"},"packages":[],"prev":{"headline":"ice: xsk: return xsk buffers back to pool when cleaning the ring","id":"CVE-2021-47105"},"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":"2026-08-05","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel's netfilter subsystem allows local attackers to potentially execute arbitrary code or escalate privileges.","url":"https://insights.sbomify.com/CVE-2021-47106/"}