{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47363 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47363 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 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-2021-47363 and fix it if it is affected.\n\nWhat it is: CVE-2021-47363 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 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-2021-47363 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-2021-47363/ (Markdown: https://insights.sbomify.com/CVE-2021-47363/index.md)","id":"CVE-2021-47363","markdown":"https://insights.sbomify.com/CVE-2021-47363/index.md","name":"CVE-2021-47363","record":{"aliases":["DEBIAN-CVE-2021-47363","GHSA-5w2f-hr95-2h6j","UBUNTU-CVE-2021-47363"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A division by zero error in the Linux kernel nexthop subsystem can cause a system crash when replacing a resilient group.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-369","name":"Divide By Zero"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: Fix division by zero while replacing a resilient group\n\nThe resilient nexthop group torture tests in fib_nexthop.sh exposed a\npossible division by zero while replacing a resilient group [1]. The\ndivision by zero occurs when the data path sees a resilient nexthop\ngroup with zero buckets.\n\nThe tests replace a resilient nexthop group in a loop while traffic is\nforwarded through it. The tests do not specify the number of buckets\nwhile performing the replacement, resulting in the kernel allocating a\nstub resilient table (i.e, 'struct nh_res_table') with zero buckets.\n\nThis table should never be visible to the data path, but the old nexthop\ngroup (i.e., 'oldg') might still be used by the data path when the stub\ntable is assigned to it.\n\nFix this by only assigning the stub table to the old nexthop group after\nmaking sure the group is no longer used by the data path.\n\nTested with fib_nexthops.sh:\n\nTests passed: 222\nTests failed:   0\n\n[1]\n divide error: 0000 [#1] PREEMPT SMP KASAN\n CPU: 0 PID: 1850 Comm: ping Not tainted 5.14.0-custom-10271-ga86eb53057fe #1107\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014\n RIP: 0010:nexthop_select_path+0x2d2/0x1a80\n[...]\n Call Trace:\n  fib_select_multipath+0x79b/0x1530\n  fib_select_path+0x8fb/0x1c10\n  ip_route_output_key_hash_rcu+0x1198/0x2da0\n  ip_route_output_key_hash+0x190/0x340\n  ip_route_output_flow+0x21/0x120\n  raw_sendmsg+0x91d/0x2e10\n  inet_sendmsg+0x9e/0xe0\n  __sys_sendto+0x23d/0x360\n  __x64_sys_sendto+0xe1/0x1b0\n  do_syscall_64+0x35/0x80\n  entry_SYSCALL_64_after_hwframe+0x44/0xae","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":"nexthop: Fix division by zero while replacing a resilient group","id":"CVE-2021-47363","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"comedi: Fix memory leak in compat_insnlist()","id":"CVE-2021-47364"},"packages":[],"prev":{"headline":"drm/amd/pm: Update intermediate power state for SI","id":"CVE-2021-47362"},"products":["Linux"],"published":"2024-05-21","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":"2026-05-11","vendors":["Linux"]},"summary":"A division by zero error in the Linux kernel nexthop subsystem can cause a system crash when replacing a resilient group.","url":"https://insights.sbomify.com/CVE-2021-47363/"}