{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-47593","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-24T15:11:00.733Z","datePublished":"2024-06-19T14:53:56.251Z","dateUpdated":"2025-05-04T07:14:25.699Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T07:14:25.699Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: clear 'kern' flag from fallback sockets\n\nThe mptcp ULP extension relies on sk->sk_sock_kern being set correctly:\nIt prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, \"mptcp\", 6); from\nworking for plain tcp sockets (any userspace-exposed socket).\n\nBut in case of fallback, accept() can return a plain tcp sk.\nIn such case, sk is still tagged as 'kernel' and setsockopt will work.\n\nThis will crash the kernel, The subflow extension has a NULL ctx->conn\nmptcp socket:\n\nBUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0\nCall Trace:\n tcp_data_ready+0xf8/0x370\n [..]"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"],"versions":[{"version":"cf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be","lessThan":"451f1eded7f56e93aaf52eb547ba97742d9c0e97","status":"affected","versionType":"git"},{"version":"cf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be","lessThan":"c26ac0ea3a91c210cf90452e625dc441adf3e549","status":"affected","versionType":"git"},{"version":"cf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be","lessThan":"d6692b3b97bdc165d150f4c1505751a323a80717","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"],"versions":[{"version":"5.6","status":"affected"},{"version":"0","lessThan":"5.6","status":"unaffected","versionType":"semver"},{"version":"5.10.88","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.11","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"5.16","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.10.88"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.15.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.16"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/451f1eded7f56e93aaf52eb547ba97742d9c0e97"},{"url":"https://git.kernel.org/stable/c/c26ac0ea3a91c210cf90452e625dc441adf3e549"},{"url":"https://git.kernel.org/stable/c/d6692b3b97bdc165d150f4c1505751a323a80717"}],"title":"mptcp: clear 'kern' flag from fallback sockets","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:47:39.485Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/451f1eded7f56e93aaf52eb547ba97742d9c0e97","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/c26ac0ea3a91c210cf90452e625dc441adf3e549","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/d6692b3b97bdc165d150f4c1505751a323a80717","tags":["x_transferred"]}]},{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47593","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T17:12:30.519015Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-09-11T17:34:52.236Z"}}]}}