{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-52463 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2023-52463 is a medium-severity vulnerability in Linux kernel, published on 23 Feb 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-2023-52463 and fix it if it is affected.\n\nWhat it is: CVE-2023-52463 is a medium-severity vulnerability in Linux kernel, published on 23 Feb 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-2023-52463 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-2023-52463/ (Markdown: https://insights.sbomify.com/CVE-2023-52463/index.md)","id":"CVE-2023-52463","markdown":"https://insights.sbomify.com/CVE-2023-52463/index.md","name":"CVE-2023-52463","record":{"aliases":["BELL-CVE-2023-52463","DEBIAN-CVE-2023-52463","GHSA-w5fp-p5rq-w697","UBUNTU-CVE-2023-52463"],"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 local attacker can crash the Linux kernel by remounting efivarfs as read-write when firmware lacks SetVariable support.","user_interaction":"not_required","vuln_class":"null_dereference"},"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-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nefivarfs: force RO when remounting if SetVariable is not supported\n\nIf SetVariable at runtime is not supported by the firmware we never assign\na callback for that function. At the same time mount the efivarfs as\nRO so no one can call that.  However, we never check the permission flags\nwhen someone remounts the filesystem as RW. As a result this leads to a\ncrash looking like this:\n\n$ mount -o remount,rw /sys/firmware/efi/efivars\n$ efi-updatevar -f PK.auth PK\n\n[  303.279166] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000\n[  303.280482] Mem abort info:\n[  303.280854]   ESR = 0x0000000086000004\n[  303.281338]   EC = 0x21: IABT (current EL), IL = 32 bits\n[  303.282016]   SET = 0, FnV = 0\n[  303.282414]   EA = 0, S1PTW = 0\n[  303.282821]   FSC = 0x04: level 0 translation fault\n[  303.283771] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004258c000\n[  303.284913] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000\n[  303.286076] Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP\n[  303.286936] Modules linked in: qrtr tpm_tis tpm_tis_core crct10dif_ce arm_smccc_trng rng_core drm fuse ip_tables x_tables ipv6\n[  303.288586] CPU: 1 PID: 755 Comm: efi-updatevar Not tainted 6.3.0-rc1-00108-gc7d0c4695c68 #1\n[  303.289748] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2023.04-00627-g88336918701d 04/01/2023\n[  303.291150] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n[  303.292123] pc : 0x0\n[  303.292443] lr : efivar_set_variable_locked+0x74/0xec\n[  303.293156] sp : ffff800008673c10\n[  303.293619] x29: ffff800008673c10 x28: ffff0000037e8000 x27: 0000000000000000\n[  303.294592] x26: 0000000000000800 x25: ffff000002467400 x24: 0000000000000027\n[  303.295572] x23: ffffd49ea9832000 x22: ffff0000020c9800 x21: ffff000002467000\n[  303.296566] x20: 0000000000000001 x19: 00000000000007fc x18: 0000000000000000\n[  303.297531] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaaac807ab54\n[  303.298495] x14: ed37489f673633c0 x13: 71c45c606de13f80 x12: 47464259e219acf4\n[  303.299453] x11: ffff000002af7b01 x10: 0000000000000003 x9 : 0000000000000002\n[  303.300431] x8 : 0000000000000010 x7 : ffffd49ea8973230 x6 : 0000000000a85201\n[  303.301412] x5 : 0000000000000000 x4 : ffff0000020c9800 x3 : 00000000000007fc\n[  303.302370] x2 : 0000000000000027 x1 : ffff000002467400 x0 : ffff000002467000\n[  303.303341] Call trace:\n[  303.303679]  0x0\n[  303.303938]  efivar_entry_set_get_size+0x98/0x16c\n[  303.304585]  efivarfs_file_write+0xd0/0x1a4\n[  303.305148]  vfs_write+0xc4/0x2e4\n[  303.305601]  ksys_write+0x70/0x104\n[  303.306073]  __arm64_sys_write+0x1c/0x28\n[  303.306622]  invoke_syscall+0x48/0x114\n[  303.307156]  el0_svc_common.constprop.0+0x44/0xec\n[  303.307803]  do_el0_svc+0x38/0x98\n[  303.308268]  el0_svc+0x2c/0x84\n[  303.308702]  el0t_64_sync_handler+0xf4/0x120\n[  303.309293]  el0t_64_sync+0x190/0x194\n[  303.309794] Code: ???????? ???????? ???????? ???????? (????????)\n[  303.310612] ---[ end trace 0000000000000000 ]---\n\nFix this by adding a .reconfigure() function to the fs operations which\nwe can use to check the requested flags and deny anything that's not RO\nif the firmware doesn't implement SetVariable at runtime.","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":"efivarfs: force RO when remounting if SetVariable is not supported","id":"CVE-2023-52463","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2023"},"n_packages":0,"n_references":6,"next":{"headline":"EDAC/thunderx: Fix possible out-of-bounds string access","id":"CVE-2023-52464"},"packages":[],"prev":{"headline":"bpf: fix check for attempt to corrupt spilled pointer","id":"CVE-2023-52462"},"products":["Linux"],"published":"2024-02-23","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 local attacker can crash the Linux kernel by remounting efivarfs as read-write when firmware lacks SetVariable support.","url":"https://insights.sbomify.com/CVE-2023-52463/"}