{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47338 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47338 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-2021-47338 and fix it if it is affected.\n\nWhat it is: CVE-2021-47338 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-2021-47338 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-2021-47338/ (Markdown: https://insights.sbomify.com/CVE-2021-47338/index.md)","id":"CVE-2021-47338","markdown":"https://insights.sbomify.com/CVE-2021-47338/index.md","name":"CVE-2021-47338","record":{"aliases":["DEBIAN-CVE-2021-47338","GHSA-m2r9-3c4r-qv68","UBUNTU-CVE-2021-47338"],"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 fbmem driver 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\nfbmem: Do not delete the mode that is still in use\n\nThe execution of fb_delete_videomode() is not based on the result of the\nprevious fbcon_mode_deleted(). As a result, the mode is directly deleted,\nregardless of whether it is still in use, which may cause UAF.\n\n==================================================================\nBUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \\\ndrivers/video/fbdev/core/modedb.c:924\nRead of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962\n\nCPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...\nCall Trace:\n __dump_stack lib/dump_stack.c:77 [inline]\n dump_stack+0x137/0x1be lib/dump_stack.c:118\n print_address_description+0x6c/0x640 mm/kasan/report.c:385\n __kasan_report mm/kasan/report.c:545 [inline]\n kasan_report+0x13d/0x1e0 mm/kasan/report.c:562\n fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924\n fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746\n fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975\n do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nFreed by task 18960:\n kasan_save_stack mm/kasan/common.c:48 [inline]\n kasan_set_track+0x3d/0x70 mm/kasan/common.c:56\n kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355\n __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422\n slab_free_hook mm/slub.c:1541 [inline]\n slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574\n slab_free mm/slub.c:3139 [inline]\n kfree+0xca/0x3d0 mm/slub.c:4121\n fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104\n fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978\n do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x44/0xa9","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":"fbmem: Do not delete the mode that is still in use","id":"CVE-2021-47338","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":5,"next":{"headline":"media: v4l2-core: explicitly clear ioctl input data","id":"CVE-2021-47339"},"packages":[],"prev":{"headline":"scsi: core: Fix bad pointer dereference when ehandler kthread is invalid","id":"CVE-2021-47337"},"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":"2026-08-05","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel's fbmem driver allows local attackers to potentially execute arbitrary code or escalate privileges.","url":"https://insights.sbomify.com/CVE-2021-47338/"}