{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-46999", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-27T18:42:55.950Z", "datePublished": "2024-02-28T08:13:22.256Z", "dateUpdated": "2026-08-05T08:45:28.974Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:45:28.974Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: do asoc update earlier in sctp_sf_do_dupcook_a\n\nThere's a panic that occurs in a few of envs, the call trace is as below:\n\n [] general protection fault, ... 0x29acd70f1000a: 0000 [#1] SMP PTI\n [] RIP: 0010:sctp_ulpevent_notify_peer_addr_change+0x4b/0x1fa [sctp]\n [] sctp_assoc_control_transport+0x1b9/0x210 [sctp]\n [] sctp_do_8_2_transport_strike.isra.16+0x15c/0x220 [sctp]\n [] sctp_cmd_interpreter.isra.21+0x1231/0x1a10 [sctp]\n [] sctp_do_sm+0xc3/0x2a0 [sctp]\n [] sctp_generate_timeout_event+0x81/0xf0 [sctp]\n\nThis is caused by a transport use-after-free issue. When processing a\nduplicate COOKIE-ECHO chunk in sctp_sf_do_dupcook_a(), both COOKIE-ACK\nand SHUTDOWN chunks are allocated with the transort from the new asoc.\nHowever, later in the sideeffect machine, the old asoc is used to send\nthem out and old asoc's shutdown_last_sent_to is set to the transport\nthat SHUTDOWN chunk attached to in sctp_cmd_setup_t2(), which actually\nbelongs to the new asoc. After the new_asoc is freed and the old asoc\nT2 timeout, the old asoc's shutdown_last_sent_to that is already freed\nwould be accessed in sctp_sf_t2_timer_expire().\n\nThanks Alexander and Jere for helping dig into this issue.\n\nTo fix it, this patch is to do the asoc update first, then allocate\nthe COOKIE-ACK and SHUTDOWN chunks with the 'updated' old asoc. This\nwould make more sense, as a chunk from an asoc shouldn't be sent out\nwith another asoc. We had fixed quite a few issues caused by this." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is in SCTP COOKIE-ECHO processing on the packet receive path (sctp_rcv → sctp_sf_do_5_2_4_dupcook → sctp_sf_do_dupcook_a); a remote peer triggers it by sending SCTP packets over IP.\nAC:L - A peer can observe SHUTDOWN, withhold SHUTDOWN-ACK to keep the victim in SHUTDOWN_SENT, then complete a restart INIT/COOKIE-ECHO exchange; the attacker controls both the timing and the packets that create the UAF.\nPR:N - No local privileges are required—any remote SCTP client that completes a normal association handshake can send the restart COOKIE-ECHO; cookie HMAC is protocol anti-DoS, not OS authentication.\nUI:N - Exploitation requires only attacker-sent SCTP packets; no victim user action beyond ordinary association close is needed.\nS:U - Impact stays within the vulnerable host kernel (transport UAF / privilege escalation or crash); it does not cross a VM, IOMMU, or other security boundary.\nC:H - This is a heap use-after-free of an sctp_transport; freed object reuse can yield arbitrary kernel read primitives.\nI:H - The same transport UAF enables heap spraying and write/control-flow hijacking primitives for integrity compromise or code execution.\nA:H - The bug causes a reproducible kernel general protection fault / panic when the T2 timer later dereferences the freed transport." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/sm_statefuns.c" ], "versions": [ { "version": "db8bf823e70f239372c62f13e4eb6f08a1665e8c", "lessThan": "d624f2991b977821375fbd56c91b0c91d456a697", "status": "affected", "versionType": "git" }, { "version": "a204d577be70e0a0a6023cf1b9859c9ebffaeecd", "lessThan": "b1b31948c0af44628e43353828453461bb74098f", "status": "affected", "versionType": "git" }, { "version": "145cb2f7177d94bc54563ed26027e952ee0ae03c", "lessThan": "f01988ecf3654f805282dce2d3bb9afe68d2691e", "status": "affected", "versionType": "git" }, { "version": "145cb2f7177d94bc54563ed26027e952ee0ae03c", "lessThan": "61b877bad9bb0d82b7d8841be50872557090a704", "status": "affected", "versionType": "git" }, { "version": "145cb2f7177d94bc54563ed26027e952ee0ae03c", "lessThan": "0bfd913c2121b3d553bfd52810fe6061d542d625", "status": "affected", "versionType": "git" }, { "version": "145cb2f7177d94bc54563ed26027e952ee0ae03c", "lessThan": "35b4f24415c854cd718ccdf38dbea6297f010aae", "status": "affected", "versionType": "git" }, { "version": "a5ce8531ea508d270822b2bc6140c6198c8a2a7b", "status": "affected", "versionType": "git" }, { "version": "4.19.123", "lessThan": "4.19.191", "status": "affected", "versionType": "semver" }, { "version": "5.4.41", "lessThan": "5.4.120", "status": "affected", "versionType": "semver" }, { "version": "5.6.13", "lessThan": "5.7", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/sm_statefuns.c" ], "versions": [ { "version": "5.7", "status": "affected" }, { "version": "0", "lessThan": "5.7", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.191", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.120", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.38", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.11.22", "lessThanOrEqual": "5.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.5", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13", "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": "4.19.123", "versionEndExcluding": "4.19.191" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.41", "versionEndExcluding": "5.4.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.10.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.11.22" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.12.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "5.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d624f2991b977821375fbd56c91b0c91d456a697" }, { "url": "https://git.kernel.org/stable/c/b1b31948c0af44628e43353828453461bb74098f" }, { "url": "https://git.kernel.org/stable/c/f01988ecf3654f805282dce2d3bb9afe68d2691e" }, { "url": "https://git.kernel.org/stable/c/61b877bad9bb0d82b7d8841be50872557090a704" }, { "url": "https://git.kernel.org/stable/c/0bfd913c2121b3d553bfd52810fe6061d542d625" }, { "url": "https://git.kernel.org/stable/c/35b4f24415c854cd718ccdf38dbea6297f010aae" } ], "title": "sctp: do asoc update earlier in sctp_sf_do_dupcook_a", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-21T16:28:23.491999Z", "id": "CVE-2021-46999", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-21T16:28:34.904Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:37.916Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/d624f2991b977821375fbd56c91b0c91d456a697", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/b1b31948c0af44628e43353828453461bb74098f", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/f01988ecf3654f805282dce2d3bb9afe68d2691e", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/61b877bad9bb0d82b7d8841be50872557090a704", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/0bfd913c2121b3d553bfd52810fe6061d542d625", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/35b4f24415c854cd718ccdf38dbea6297f010aae", "tags": [ "x_transferred" ] } ] } ] } }