CVE-2025-40133

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-40133", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.170Z", "datePublished": "2025-11-12T10:23:22.498Z", "dateUpdated": "2026-08-05T12:07:59.353Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:07:59.353Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable().\n\nmptcp_active_enable() is called from subflow_finish_connect(),\nwhich is icsk->icsk_af_ops->sk_rx_dst_set() and it's not always\nunder RCU.\n\nUsing sk_dst_get(sk)->dev could trigger UAF.\n\nLet's use __sk_dst_get() and dst_dev_rcu()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The stale `dst->dev` dereference executes while processing a remote peer's SYN-ACK \u2014 `tcp_finish_connect()` \u2192 `icsk_af_ops->sk_rx_dst_set()` \u2192 `subflow_finish_connect()` \u2192 `mptcp_active_enable()` \u2014 so remote network data drives entry into the vulnerable code, and the peer also controls the MP_CAPABLE/blackhole state that unlocks the guarded block. Any MPTCP-enabled host making outbound connections (mobile/carrier stacks, mptcpize'd services, MPTCP proxies) is exposed to a malicious or on-path server.\nAC:H - The attacker controls one side of the race (when the SYN-ACK arrives and thus when `dst->dev` is read), but the other side requires the route's `net_device` to be concurrently unregistered so `dst_dev_put()`/`netdev_ref_replace()` drops the last reference and `free_netdev()` runs \u2014 a local netdev-teardown event a remote peer can neither induce nor time, as is landing the SYN-ACK in the socket backlog (non-RCU process context) rather than softirq.\nPR:N - The vulnerable code runs during the TCP/MPTCP handshake itself, before any application-level authentication or credential exchange, so the remote peer needs no privileges or account of any kind on the target.\nUI:N - Outbound MPTCP connections are made automatically by daemons, mobile connectivity stacks, and proxies without any human action, and an on-path attacker can simply inject the MP_CAPABLE SYN-ACK for a connection the host initiates on its own.\nS:U - The use-after-free is on a kernel `struct net_device` and its effects stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is a use-after-free read of a freed, heap-sprayable `net_device`, and a reclaimed slab can be groomed with attacker-influenced data, giving a read primitive over reclaimed kernel memory; the value read (`dev->flags & IFF_LOOPBACK`) further acts as an oracle since it determines whether `active_disable_times` is cleared, which is observable through subsequent MPTCP fallback behaviour and the MPTCP MIB counters.\nI:H - A use-after-free on a `net_device` is a heap-corruption primitive whose reclaimed contents are attacker-influenceable via spraying, and here freed memory directly steers a kernel state write (`atomic_set(&pernet->active_disable_times, 0)`), letting uncontrolled reclaimed data modify per-namespace MPTCP protocol state and, once the slab is groomed, be escalated toward arbitrary write and control-flow hijack.\nA:H - Dereferencing a freed `net_device` \u2014 allocated with `kvzalloc` and potentially unmapped on free \u2014 reliably produces a kernel oops or panic even when not weaponized, and the trigger can be retried indefinitely for a persistent denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mptcp/ctrl.c"], "versions": [{"version": "27069e7cb3d1cea9377069266acf19b9cc5ad0ae", "lessThan": "ad16235c9d3ef7ec17c109ff39b7504f49d17072", "status": "affected", "versionType": "git"}, {"version": "27069e7cb3d1cea9377069266acf19b9cc5ad0ae", "lessThan": "cc976ec9e38bb79409de3261ba1dbb6868e2a53e", "status": "affected", "versionType": "git"}, {"version": "27069e7cb3d1cea9377069266acf19b9cc5ad0ae", "lessThan": "893c49a78d9f85e4b8081b908fb7c407d018106a", "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/ctrl.c"], "versions": [{"version": "6.12", "status": "affected"}, {"version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.55", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17.3", "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": "6.12", "versionEndExcluding": "6.12.55"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.17.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/ad16235c9d3ef7ec17c109ff39b7504f49d17072"}, {"url": "https://git.kernel.org/stable/c/cc976ec9e38bb79409de3261ba1dbb6868e2a53e"}, {"url": "https://git.kernel.org/stable/c/893c49a78d9f85e4b8081b908fb7c407d018106a"}], "title": "mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable().", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/mptcp/ctrl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "ad16235c9d3ef7ec17c109ff39b7504f49d17072", "status": "affected", "version": "27069e7cb3d1cea9377069266acf19b9cc5ad0ae", "versionType": "git"}, {"lessThan": "cc976ec9e38bb79409de3261ba1dbb6868e2a53e", "status": "affected", "version": "27069e7cb3d1cea9377069266acf19b9cc5ad0ae", "versionType": "git"}, {"lessThan": "893c49a78d9f85e4b8081b908fb7c407d018106a", "status": "affected", "version": "27069e7cb3d1cea9377069266acf19b9cc5ad0ae", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/mptcp/ctrl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.12"}, {"lessThan": "6.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.55", "versionType": "semver"}, {"lessThanOrEqual": "6.17.*", "status": "unaffected", "version": "6.17.3", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.18", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable().\n\nmptcp_active_enable() is called from subflow_finish_connect(),\nwhich is icsk->icsk_af_ops->sk_rx_dst_set() and it's not always\nunder RCU.\n\nUsing sk_dst_get(sk)->dev could trigger UAF.\n\nLet's use __sk_dst_get() and dst_dev_rcu()."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmptcp: Usar __sk_dst_get() y dst_dev_rcu() en mptcp_active_enable().\n\nmptcp_active_enable() es llamada desde subflow_finish_connect(),\nque es icsk->icsk_af_ops->sk_rx_dst_set() y no siempre est\u00e1 bajo RCU.\n\nUsar sk_dst_get(sk)->dev podr\u00eda desencadenar UAF.\n\nUsemos __sk_dst_get() y dst_dev_rcu()."}], "id": "CVE-2025-40133", "lastModified": "2026-10-19T21:10:00.160", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2025-11-12T11:15:42.993", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/893c49a78d9f85e4b8081b908fb7c407d018106a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ad16235c9d3ef7ec17c109ff39b7504f49d17072"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cc976ec9e38bb79409de3261ba1dbb6868e2a53e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Deferred"}

{"bugzilla": {"description": "kernel: mptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable()", "id": "2414465", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2414465"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nmptcp: Use __sk_dst_get() and dst_dev_rcu() in mptcp_active_enable().\nmptcp_active_enable() is called from subflow_finish_connect(),\nwhich is icsk->icsk_af_ops->sk_rx_dst_set() and it's not always\nunder RCU.\nUsing sk_dst_get(sk)->dev could trigger UAF.\nLet's use __sk_dst_get() and dst_dev_rcu()."], "name": "CVE-2025-40133", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-11-12T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-40133\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-40133\nhttps://lore.kernel.org/linux-cve-announce/2025111254-CVE-2025-40133-4d9d@gregkh/T"], "threat_severity": "Important"}

{"created": "2025-11-12T22:12:35.526308+00:00", "updated": "2025-11-12T22:12:35.526336+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}