{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47092 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47092 is a medium-severity denial of service 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-2021-47092 and fix it if it is affected.\n\nWhat it is: CVE-2021-47092 is a medium-severity denial of service 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-2021-47092 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-2021-47092/ (Markdown: https://insights.sbomify.com/CVE-2021-47092/index.md)","id":"CVE-2021-47092","markdown":"https://insights.sbomify.com/CVE-2021-47092/index.md","name":"CVE-2021-47092","record":{"aliases":["DEBIAN-CVE-2021-47092","GHSA-hg5r-659j-4p32","UBUNTU-CVE-2021-47092"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel KVM","requires_auth":"low_privilege","summary":"A logic error in KVM VMX handling can trigger a kernel warning and potential instability during VM teardown, allowing local attackers to cause denial of service.","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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: VMX: Always clear vmx-\u003efail on emulation_required\n\nRevert a relatively recent change that set vmx-\u003efail if the vCPU is in L2\nand emulation_required is true, as that behavior is completely bogus.\nSetting vmx-\u003efail and synthesizing a VM-Exit is contradictory and wrong:\n\n  (a) it's impossible to have both a VM-Fail and VM-Exit\n  (b) vmcs.EXIT_REASON is not modified on VM-Fail\n  (c) emulation_required refers to guest state and guest state checks are\n      always VM-Exits, not VM-Fails.\n\nFor KVM specifically, emulation_required is handled before nested exits\nin __vmx_handle_exit(), thus setting vmx-\u003efail has no immediate effect,\ni.e. KVM calls into handle_invalid_guest_state() and vmx-\u003efail is ignored.\nSetting vmx-\u003efail can ultimately result in a WARN in nested_vmx_vmexit()\nfiring when tearing down the VM as KVM never expects vmx-\u003efail to be set\nwhen L2 is active, KVM always reflects those errors into L1.\n\n  ------------[ cut here ]------------\n  WARNING: CPU: 0 PID: 21158 at arch/x86/kvm/vmx/nested.c:4548\n                                nested_vmx_vmexit+0x16bd/0x17e0\n                                arch/x86/kvm/vmx/nested.c:4547\n  Modules linked in:\n  CPU: 0 PID: 21158 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n  RIP: 0010:nested_vmx_vmexit+0x16bd/0x17e0 arch/x86/kvm/vmx/nested.c:4547\n  Code: \u003c0f\u003e 0b e9 2e f8 ff ff e8 57 b3 5d 00 0f 0b e9 00 f1 ff ff 89 e9 80\n  Call Trace:\n   vmx_leave_nested arch/x86/kvm/vmx/nested.c:6220 [inline]\n   nested_vmx_free_vcpu+0x83/0xc0 arch/x86/kvm/vmx/nested.c:330\n   vmx_free_vcpu+0x11f/0x2a0 arch/x86/kvm/vmx/vmx.c:6799\n   kvm_arch_vcpu_destroy+0x6b/0x240 arch/x86/kvm/x86.c:10989\n   kvm_vcpu_destroy+0x29/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:441\n   kvm_free_vcpus arch/x86/kvm/x86.c:11426 [inline]\n   kvm_arch_destroy_vm+0x3ef/0x6b0 arch/x86/kvm/x86.c:11545\n   kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1189 [inline]\n   kvm_put_kvm+0x751/0xe40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1220\n   kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3489\n   __fput+0x3fc/0x870 fs/file_table.c:280\n   task_work_run+0x146/0x1c0 kernel/task_work.c:164\n   exit_task_work include/linux/task_work.h:32 [inline]\n   do_exit+0x705/0x24f0 kernel/exit.c:832\n   do_group_exit+0x168/0x2d0 kernel/exit.c:929\n   get_signal+0x1740/0x2120 kernel/signal.c:2852\n   arch_do_signal_or_restart+0x9c/0x730 arch/x86/kernel/signal.c:868\n   handle_signal_work kernel/entry/common.c:148 [inline]\n   exit_to_user_mode_loop kernel/entry/common.c:172 [inline]\n   exit_to_user_mode_prepare+0x191/0x220 kernel/entry/common.c:207\n   __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]\n   syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300\n   do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86\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":"KVM: VMX: Always clear vmx-\u003efail on emulation_required","id":"CVE-2021-47092","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":"platform/x86: intel_pmc_core: fix memleak on registration failure","id":"CVE-2021-47093"},"packages":[],"prev":{"headline":"mac80211: fix locking in ieee80211_start_ap error path","id":"CVE-2021-47091"},"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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A logic error in KVM VMX handling can trigger a kernel warning and potential instability during VM teardown, allowing local attackers to cause denial of service.","url":"https://insights.sbomify.com/CVE-2021-47092/"}