{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21791", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.766Z", "datePublished": "2025-02-27T02:18:29.014Z", "dateUpdated": "2026-08-05T11:54:28.163Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:28.163Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvrf: use RCU protection in l3mdev_l3_out()\n\nl3mdev_l3_out() can be called without RCU being held:\n\nraw_sendmsg()\n ip_push_pending_frames()\n ip_send_skb()\n ip_local_out()\n __ip_local_out()\n l3mdev_ip_out()\n\nAdd rcu_read_lock() / rcu_read_unlock() pair to avoid\na 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 - Both halves of the race are driven from the local system — a `sendmsg()` on a local socket for the read side, and RTNL link operations (VRF delete/unenslave) for the free side. A remote peer cannot induce the VRF teardown that arms the use-after-free.\nAC:L - The attacker controls both sides of the race and can loop them indefinitely: one thread sends UDP/raw packets out a VRF-enslaved device while another repeatedly unenslaves/deletes the VRF master, with preemption pressure raised at will. `do_vrf_del_slave()` widens the window further by unlinking the adjacency before clearing `IFF_L3MDEV_SLAVE`.\nPR:L - The transmit side needs no privileges at all (ordinary UDP sendmsg), and the VRF create/enslave/delete side needs only CAP_NET_ADMIN within a network namespace, which an unprivileged user obtains via `unshare -Urn`.\nUI:N - The attacker's own threads perform every step — socket sends and netlink link operations — with no victim action required.\nS:U - The use-after-free and its consequences are confined to the kernel's own security authority; no VM, IOMMU, or other trust boundary is crossed.\nC:H - The freed `netdev_adjacent` sits in a general kmalloc cache and is readily groomed, letting the attacker supply `upper->dev`, after which `master->l3mdev_ops` and `->l3mdev_l3_out` are read from an attacker-chosen address — an arbitrary kernel read primitive.\nI:H - The same reclaimed object yields an indirect call through an attacker-controlled function pointer with `master` as the first argument, giving control-flow hijack and thus arbitrary kernel-state modification.\nA:H - Even unweaponized, dereferencing a stale adjacency entry and calling through garbage function pointers reliably oopses or panics the kernel, and the attacker can retrigger it at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/l3mdev.h" ], "versions": [ { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "6ccaa5797f5362a2aad6baa6ddaf4715ac2dd51e", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "20a3489b396764cc9376e32a9172bee26a89dc3b", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "5bb4228c32261d06e4fbece37ec3828bcc005b6b", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "c7574740be8ce68a57d0aece24987b9be2114c3c", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "c40cb5c03e37552d6eff963187109e2c3f78ef6f", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "022cac1c693add610ae76ede03adf4d9d5a2cf21", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "7b81425b517accefd46bee854d94954f5c57e019", "status": "affected", "versionType": "git" }, { "version": "a8e3e1a9f02094145580ea7920c6a1d9aabd5539", "lessThan": "6d0ce46a93135d96b7fa075a94a88fe0da8e8773", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/l3mdev.h" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "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": "4.9", "versionEndExcluding": "5.4.291" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.6.79" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.12.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.13.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6ccaa5797f5362a2aad6baa6ddaf4715ac2dd51e" }, { "url": "https://git.kernel.org/stable/c/20a3489b396764cc9376e32a9172bee26a89dc3b" }, { "url": "https://git.kernel.org/stable/c/5bb4228c32261d06e4fbece37ec3828bcc005b6b" }, { "url": "https://git.kernel.org/stable/c/c7574740be8ce68a57d0aece24987b9be2114c3c" }, { "url": "https://git.kernel.org/stable/c/c40cb5c03e37552d6eff963187109e2c3f78ef6f" }, { "url": "https://git.kernel.org/stable/c/022cac1c693add610ae76ede03adf4d9d5a2cf21" }, { "url": "https://git.kernel.org/stable/c/7b81425b517accefd46bee854d94954f5c57e019" }, { "url": "https://git.kernel.org/stable/c/6d0ce46a93135d96b7fa075a94a88fe0da8e8773" } ], "title": "vrf: use RCU protection in l3mdev_l3_out()", "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-2025-21791", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-27T17:57:16.236835Z" } } } ], "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": "2025-02-27T18:02:26.723Z" } }, { "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": "2025-11-03T20:59:34.647Z" } } ] } }