{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40187", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.177Z", "datePublished": "2025-11-12T21:56:29.504Z", "dateUpdated": "2026-08-05T12:08:25.629Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:08:25.629Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce()\n\nIf new_asoc->peer.adaptation_ind=0 and sctp_ulpevent_make_authkey=0\nand sctp_ulpevent_make_authkey() returns 0, then the variable\nai_ev remains zero and the zero will be dereferenced\nin the sctp_ulpevent_free() function." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is in the SCTP state machine's COOKIE ECHO handler, driven entirely by chunks received from a remote peer over IP, and is reached from `sctp_rcv()` in NET_RX softirq context. Any host with a listening SCTP socket (telecom SIGTRAN/M3UA/Diameter signalling nodes are routinely inter-carrier and internet facing) is remotely reachable.\nAC:L - The attacker deterministically controls both selectable preconditions by simply omitting the Adaptation Layer Indication parameter (leaving `ai_ev` NULL) and omitting the SCTP-AUTH parameters (forcing the `sctp_ulpevent_make_authkey()` call), which are the default characteristics of a plain handshake. The only remaining factor is the GFP_ATOMIC allocation failing, which the attacker can influence by flooding the target with concurrent association attempts and traffic to exhaust atomic reserves — particularly effective on the memory-constrained embedded/telecom devices where SCTP is deployed.\nPR:N - SCTP association establishment is entirely unauthenticated; the attacker only needs to complete the standard INIT / INIT-ACK / COOKIE ECHO exchange against a listening socket, with the state cookie having been minted by the victim itself. No credentials, capabilities, or local account are involved anywhere along the path.\nUI:N - Exploitation requires nothing from any local user or administrator beyond the pre-existing condition that an SCTP service is listening. The attacker drives the entire handshake unilaterally.\nS:U - The NULL dereference faults inside the kernel handling the same network stack that received the packet; there is no crossing into another security authority such as a hypervisor, IOMMU, or sandbox boundary.\nC:N - The dereference is a read of `event->msg_flags` at a fixed low offset from NULL, which faults immediately; no data is returned to the attacker and no kernel memory contents are disclosed.\nI:N - The bug is a read fault on a NULL pointer with no write, no out-of-bounds access, and no object lifetime confusion, so no kernel data is modified and no control-flow hijack primitive is produced.\nA:H - The dereference occurs in NET_RX softirq context, producing a fatal exception in interrupt — a kernel panic and complete loss of availability, or at minimum an oops that kills the softirq path (and an immediate panic on the `panic_on_oops` configurations common in embedded and telecom deployments). The attacker can repeat the attempt indefinitely across reboots." } ] } ], "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": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "1014b83778c8677f1d7a57c26dc728baa801ac62", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "7f702f85df0266ed7b5bab81ba50394c92f3c928", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "dbceedc0213e75bf3e9f9f9e2f66b10699d004fe", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "025419f4e216a3ae0d0cec622262e98e8078c447", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "c21f45cfa4a9526b34d76b397c9ef080668b6e73", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "d0e8f1445c19b1786759ba72a38267e1449bab7e", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "badbd79313e6591616c1b78e29a9b71efed7f035", "status": "affected", "versionType": "git" }, { "version": "30f6ebf65bc46161c5aaff1db2e6e7c76aa4a06b", "lessThan": "2f3119686ef50319490ccaec81a575973da98815", "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/sctp/sm_statefuns.c" ], "versions": [ { "version": "4.17", "status": "affected" }, { "version": "0", "lessThan": "4.17", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.301", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.246", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.195", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.157", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.113", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.54", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.4", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "4.17", "versionEndExcluding": "5.4.301" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.10.246" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "5.15.195" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.1.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.6.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.12.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.17.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/1014b83778c8677f1d7a57c26dc728baa801ac62" }, { "url": "https://git.kernel.org/stable/c/7f702f85df0266ed7b5bab81ba50394c92f3c928" }, { "url": "https://git.kernel.org/stable/c/dbceedc0213e75bf3e9f9f9e2f66b10699d004fe" }, { "url": "https://git.kernel.org/stable/c/025419f4e216a3ae0d0cec622262e98e8078c447" }, { "url": "https://git.kernel.org/stable/c/c21f45cfa4a9526b34d76b397c9ef080668b6e73" }, { "url": "https://git.kernel.org/stable/c/d0e8f1445c19b1786759ba72a38267e1449bab7e" }, { "url": "https://git.kernel.org/stable/c/badbd79313e6591616c1b78e29a9b71efed7f035" }, { "url": "https://git.kernel.org/stable/c/2f3119686ef50319490ccaec81a575973da98815" } ], "title": "net/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce()", "x_generator": { "engine": "bippy-1.2.0" } } } }