{"id":"CVE-2023-54243","title":"netfilter: ebtables: fix table blob use-after-free","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ebtables: fix table blob use-after-free\n\nWe are not allowed to return an error at this point.\nLooking at the code it looks like ret is always 0 at this\npoint…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < 9060abce3305ab2354c892c09d5689df51486df5","Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < dbb3cbbf03b3c52cb390fabec357f1e4638004f5","Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < 3dd6ac973351308d4117eda32298a9f1d68764fd","Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < cda0e0243bd3c04008fcd37a46b0269fb3c49249","Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < e58a171d35e32e6e8c37cfe0e8a94406732a331f","Linux a3bc0f8ea439762aa62d40a295157410498cbea7","Linux 8ed40c122919cd79bc3c059e5864e5e7d9d455f0","Linux c5e4ef499cfc78de45a4f01b8c557b5964d77c53","Linux f34728610b2a8c7b9864f9404f2884c17f6fca5c","Linux 8b5740915a9faa8b1fa9166193a33e2a9ae30ec6","Linux >= 3.2.60 < 3.3","Linux >= 3.4.91 < 3.5","Linux >= 3.10.41 < 3.11","Linux >= 3.12.21 < 3.13","Linux >= 3.14.5 < 3.15","Linux 3.15"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:39:46.179216Z"},"published":"2025-12-30","updated":"2026-10-15","sourceUpdated":"2026-10-15T21:41:43.012Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-54243","references":[{"url":"https://git.kernel.org/stable/c/9060abce3305ab2354c892c09d5689df51486df5"},{"url":"https://git.kernel.org/stable/c/dbb3cbbf03b3c52cb390fabec357f1e4638004f5"},{"url":"https://git.kernel.org/stable/c/3dd6ac973351308d4117eda32298a9f1d68764fd"},{"url":"https://git.kernel.org/stable/c/cda0e0243bd3c04008fcd37a46b0269fb3c49249"},{"url":"https://git.kernel.org/stable/c/e58a171d35e32e6e8c37cfe0e8a94406732a331f"}],"tags":["cve.org"],"epss":0.0015,"epssPercentile":0.03742,"ingestedAt":"2026-10-15T22:48:25.436Z","slug":"CVE-2023-54243","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ebtables: fix table blob use-after-free\n\nWe are not allowed to return an error at this point.\nLooking at the code it looks like ret is always 0 at this\npoint, but its not.\n\nt = find_table_lock(net, repl->name, &ret, &ebt_mutex);\n\n... this can return a valid table, with ret != 0.\n\nThis bug causes update of table->private with the new\nblob, but then frees the blob right away in the caller.\n\nSyzbot report:\n\nBUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168\nRead of size 4 at addr ffffc90005425000 by task kworker/u4:4/74\nWorkqueue: netns cleanup_net\nCall Trace:\n kasan_report+0xbf/0x1f0 mm/kasan/report.c:517\n __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168\n ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372\n ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169\n cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613\n...\n\nip(6)tables appears to be ok (ret should be 0 at this point) but make\nthis more obvious.\n\n## Affected\n\n- `Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < 9060abce3305ab2354c892c09d5689df51486df5`\n- `Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < dbb3cbbf03b3c52cb390fabec357f1e4638004f5`\n- `Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < 3dd6ac973351308d4117eda32298a9f1d68764fd`\n- `Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < cda0e0243bd3c04008fcd37a46b0269fb3c49249`\n- `Linux >= c58dd2dd443c26d856a168db108a0cd11c285bf3 < e58a171d35e32e6e8c37cfe0e8a94406732a331f`\n- `Linux a3bc0f8ea439762aa62d40a295157410498cbea7`\n- `Linux 8ed40c122919cd79bc3c059e5864e5e7d9d455f0`\n- `Linux c5e4ef499cfc78de45a4f01b8c557b5964d77c53`\n- `Linux f34728610b2a8c7b9864f9404f2884c17f6fca5c`\n- `Linux 8b5740915a9faa8b1fa9166193a33e2a9ae30ec6`\n- `Linux >= 3.2.60 < 3.3`\n- `Linux >= 3.4.91 < 3.5`\n- `Linux >= 3.10.41 < 3.11`\n- `Linux >= 3.12.21 < 3.13`\n- `Linux >= 3.14.5 < 3.15`\n- `Linux 3.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}