{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47342 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47342 is a high-severity use after free 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-2021-47342 and fix it if it is affected.\n\nWhat it is: CVE-2021-47342 is a high-severity use after free 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-2021-47342 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-2021-47342/ (Markdown: https://insights.sbomify.com/CVE-2021-47342/index.md)","id":"CVE-2021-47342","markdown":"https://insights.sbomify.com/CVE-2021-47342/index.md","name":"CVE-2021-47342","record":{"aliases":["DEBIAN-CVE-2021-47342","GHSA-c5qq-qcr6-82vp","UBUNTU-CVE-2021-47342"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel ext4","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel ext4 filesystem allows a use-after-free when remounting MMP-protected filesystems read-only, potentially leading to crashes or code execution.","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":"nvd","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\next4: fix possible UAF when remounting r/o a mmp-protected file system\n\nAfter commit 618f003199c6 (\"ext4: fix memory leak in\next4_fill_super\"), after the file system is remounted read-only, there\nis a race where the kmmpd thread can exit, causing sbi-\u003es_mmp_tsk to\npoint at freed memory, which the call to ext4_stop_mmpd() can trip\nover.\n\nFix this by only allowing kmmpd() to exit when it is stopped via\next4_stop_mmpd().\n\nBug-Report-Link: \u003c20210629143603.2166962-1-yebin10@huawei.com\u003e","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":"ext4: fix possible UAF when remounting r/o a mmp-protected file system","id":"CVE-2021-47342","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":3,"next":{"headline":"dm btree remove: assign new_root only when removal succeeds","id":"CVE-2021-47343"},"packages":[],"prev":{"headline":"KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio","id":"CVE-2021-47341"},"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":"2026-05-23","vendors":["Linux"]},"summary":"A race condition in the Linux kernel ext4 filesystem allows a use-after-free when remounting MMP-protected filesystems read-only, potentially leading to crashes or code execution.","url":"https://insights.sbomify.com/CVE-2021-47342/"}