{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21763", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.761Z", "datePublished": "2025-02-27T02:18:15.078Z", "dateUpdated": "2026-08-05T11:54:16.348Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:16.348Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nneighbour: use RCU protection in __neigh_notify()\n\n__neigh_notify() can be called without RTNL or RCU protection.\n\nUse RCU protection to avoid potential UAF." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The decisive side of the race — `dev_net_set()` during netdevice namespace migration or `default_device_exit_batch()` on netns teardown, followed by freeing the `struct net` — is driven only by local syscalls (`unshare(CLONE_NEWNET|CLONE_NEWUSER)`, RTM_NEWLINK/RTM_SETLINK). A purely remote or adjacent peer can generate ARP/NDISC traffic to reach `__neigh_notify()` but cannot cause the namespace pointer to go stale.\nAC:L - The attacker controls both sides: they spin a loop creating/destroying network namespaces with veth devices while concurrently driving neighbour add/update/GC notifications on other CPUs, so the race is created rather than waited for. Per race-condition guidance, attacker-created races are Low even though the window between the `dev_net()` load and the `net->rtnl` dereference is narrow.\nPR:L - `unshare -Urn` grants namespace-relative CAP_NET_ADMIN (`ns_capable(net->user_ns, CAP_NET_ADMIN)`), letting an ordinary unprivileged user create netns, create and move veth pairs, and trigger the teardown path; no real root is needed. Neighbour-table activity that reaches `__neigh_notify()` is likewise available to any unprivileged process.\nUI:N - The attacker triggers both the namespace teardown and the neighbour notifications entirely from their own processes. No victim action, mount, or file open is involved.\nS:U - The use-after-free and its consequences are confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed. This is standard in-kernel corruption leading to local privilege escalation.\nC:H - The freed `struct net` is a reclaimable `net_cachep` slab object, and `net->rtnl` is subsequently consumed as a `struct sock *` by `netlink_set_err()`/`nlmsg_notify()`, which read `sk->sk_protocol` and `sock_net(sk)` and walk netlink tables from it. Heap-spraying the freed object turns this into an attacker-directed kernel read primitive.\nI:H - With the freed `struct net` reclaimed under attacker control, `netlink_set_err()` writes through the forged `sk` pointer (`sk->sk_err = err`, list/waitqueue manipulation), giving a controlled kernel write usable for control-flow hijacking. Per guidance, use-after-free is scored High for integrity.\nA:H - Even without successful reclaim, dereferencing the freed `struct net` and the dangling `net->rtnl` socket causes a kernel oops or panic in `nlmsg_notify()`/`netlink_set_err()`. The trigger loop can be repeated indefinitely by an unprivileged user." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/neighbour.c" ], "versions": [ { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "e1aed6be381bcd7f46d4ca9d7ef0f5f3d6a1be32", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "8666e9aab801328c1408a19fbf4070609dc0695a", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "40d8f2f2a373b6c294ffac394d2bb814b572ead1", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "784eb2376270e086f7db136d154b8404edacf97b", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "1cbb2aa90cd3fba15ad7efb5cdda28f3d1082379", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "cdd5c2a12ddad8a77ce1838ff9f29aa587de82df", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "559307d25235e24b5424778c7332451b6c741159", "status": "affected", "versionType": "git" }, { "version": "426b5303eb435d98b9bee37a807be386bc2b3320", "lessThan": "becbd5850c03ed33b232083dd66c6e38c0c0e569", "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/core/neighbour.c" ], "versions": [ { "version": "2.6.25", "status": "affected" }, { "version": "0", "lessThan": "2.6.25", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.291", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.79", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.16", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.4", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "2.6.25", "versionEndExcluding": "5.4.291" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.6.79" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.12.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.13.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.25", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e1aed6be381bcd7f46d4ca9d7ef0f5f3d6a1be32" }, { "url": "https://git.kernel.org/stable/c/8666e9aab801328c1408a19fbf4070609dc0695a" }, { "url": "https://git.kernel.org/stable/c/40d8f2f2a373b6c294ffac394d2bb814b572ead1" }, { "url": "https://git.kernel.org/stable/c/784eb2376270e086f7db136d154b8404edacf97b" }, { "url": "https://git.kernel.org/stable/c/1cbb2aa90cd3fba15ad7efb5cdda28f3d1082379" }, { "url": "https://git.kernel.org/stable/c/cdd5c2a12ddad8a77ce1838ff9f29aa587de82df" }, { "url": "https://git.kernel.org/stable/c/559307d25235e24b5424778c7332451b6c741159" }, { "url": "https://git.kernel.org/stable/c/becbd5850c03ed33b232083dd66c6e38c0c0e569" } ], "title": "neighbour: use RCU protection in __neigh_notify()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2025-21763", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-27T17:57:24.552153Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T18:02:26.961Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:37:14.329Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T12:03:44.302Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html" } ] } ] } }