{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-39965", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.149Z", "datePublished": "2025-10-13T13:48:31.033Z", "dateUpdated": "2026-08-05T12:06:34.191Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:06:34.191Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: xfrm_alloc_spi shouldn't use 0 as SPI\n\nx->id.spi == 0 means \"no SPI assigned\", but since commit\n94f39804d891 (\"xfrm: Duplicate SPI Handling\"), we now create states\nand add them to the byspi list with this value.\n\n__xfrm_state_delete doesn't remove those states from the byspi list,\nsince they shouldn't be there, and this shows up as a UAF the next\ntime we go through the byspi list." } ], "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 vulnerability is reached through the XFRM_MSG_ALLOCSPI message on a NETLINK_XFRM socket, which requires local system access. Although the dangling byspi entry can subsequently be dereferenced by a received ESP/AH packet, creating the SPI-0 state requires the local netlink path.\nAC:L - The attacker deterministically triggers the bug by requesting min=max=0, which verify_spi_info() accepts, then deleting the state via DELSA/FLUSHSA; there is no race, no memory-layout dependency, and no non-default config beyond ubiquitous CONFIG_XFRM_USER.\nPR:L - xfrm_user_rcv_msg() gates on netlink_net_capable(skb, CAP_NET_ADMIN), which is evaluated against the net namespace's user_ns, so any unprivileged user obtains it via \"unshare -Urn\". This is Low, not High.\nUI:N - The full sequence — allocate SPI 0, delete the state, re-walk the byspi hash — is performed entirely by the attacker's own process with no victim action required.\nS:U - The freed xfrm_state and the corrupted hash list both live in the kernel's own security authority; this is standard kernel memory corruption with no VM, IOMMU, or hypervisor boundary crossed.\nC:H - The dangling xfrm_state remains in a global RCU hash and is read back and returned as a live SA, so a reclaimed object leaks adjacent heap contents and crypto/key state, and the UAF can be escalated into an arbitrary kernel read primitive.\nI:H - Walkers perform refcount_inc_not_zero on the freed object (a write to freed memory) and then use it as a live SA whose type/mode function-pointer fields the attacker can control by re-spraying the xfrm_state slab, yielding control-flow hijack and arbitrary write.\nA:H - Dereferencing the freed state during byspi traversal, hash resize, or netns teardown (WARN_ON(!hlist_empty())) reliably produces a KASAN-detected use-after-free, list corruption, and kernel panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/xfrm/xfrm_state.c" ], "versions": [ { "version": "3d8090bb53424432fa788fe9a49e8ceca74f0544", "lessThan": "0baf92d0b1590b903c1f4ead75e61715e50e8146", "status": "affected", "versionType": "git" }, { "version": "2fc5b54368a1bf1d2d74b4d3b8eea5309a653e38", "lessThan": "9fcedabaae0096f712bbb4ccca6a8538af1cd1c8", "status": "affected", "versionType": "git" }, { "version": "29e9158f91f99057dbd35db5e8674d93b38549fe", "lessThan": "a78e55776522373c446f18d5002a8de4b09e6bf7", "status": "affected", "versionType": "git" }, { "version": "94f39804d891cffe4ce17737d295f3b195bc7299", "lessThan": "cd8ae32e4e4652db55bce6b9c79267d8946765a9", "status": "affected", "versionType": "git" }, { "version": "c67d4e7a8f90fb6361ca89d4d5c9a28f4e935e47", "status": "affected", "versionType": "git" }, { "version": "6.15.11", "lessThan": "6.16", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/xfrm/xfrm_state.c" ], "versions": [ { "version": "6.6.103", "lessThan": "6.6.109", "status": "affected", "versionType": "semver" }, { "version": "6.12.43", "lessThan": "6.12.50", "status": "affected", "versionType": "semver" }, { "version": "6.16.2", "lessThan": "6.16.10", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.103", "versionEndExcluding": "6.6.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.43", "versionEndExcluding": "6.12.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16.2", "versionEndExcluding": "6.16.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0baf92d0b1590b903c1f4ead75e61715e50e8146" }, { "url": "https://git.kernel.org/stable/c/9fcedabaae0096f712bbb4ccca6a8538af1cd1c8" }, { "url": "https://git.kernel.org/stable/c/a78e55776522373c446f18d5002a8de4b09e6bf7" }, { "url": "https://git.kernel.org/stable/c/cd8ae32e4e4652db55bce6b9c79267d8946765a9" } ], "title": "xfrm: xfrm_alloc_spi shouldn't use 0 as SPI", "x_generator": { "engine": "bippy-1.2.0" } } } }