{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21762", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.761Z", "datePublished": "2025-02-27T02:18:14.600Z", "dateUpdated": "2026-08-05T11:54:15.248Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:15.248Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narp: use RCU protection in arp_xmit()\n\narp_xmit() 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: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 unprotected `arp_xmit()` calls are driven by the neighbour-resolution path (`neigh_timer_handler` → `neigh_probe` → `arp_solicit`), which a remote off-link attacker triggers at will by sending traffic to a Linux router/gateway that must resolve on-link next hops, as well as by ARP frames processed in `arp_process()`/bridge neigh-suppression. The vulnerable code is bound to the network stack and reachable from remotely originated packets, so Network is the correct and higher-severity classification.\nAC:H - The attacker fully controls and can sustain the ARP-transmit side of the race, but the other side — a `struct net` being freed via `cleanup_net()` or a device migrating namespaces — is background system activity the network attacker cannot command. Because that condition lies outside attacker control, complexity is High.\nPR:N - There is no capability check, credential check, or authentication gate anywhere on the path from packet receipt/neighbour resolution to `arp_xmit()`; ARP solicitation and reply generation happen unconditionally in softirq context. An entirely unauthenticated attacker reaches the vulnerable code.\nUI:N - The attacker's own packets cause the kernel to emit ARP and execute the vulnerable code; no victim must mount a filesystem, open a file, or take any other action.\nS:U - The use-after-free of `struct net` and the resulting corruption stay entirely within the kernel's own security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - A use-after-free of `struct net` lets `nf_hook()` read `net->nf.hooks_arp[]` and every ARP-family hook read `state->net` out of freed, potentially reallocated slab memory. Per kernel guidance a UAF gives the attacker control over the freed object's contents and thus an arbitrary kernel-memory read primitive.\nI:H - The stale `net` yields a `hook_head` pointer from freed memory, and `nf_hook_slow()` then performs an indirect call through `e->hooks[s].hook` — a direct function-pointer hijack primitive if the netns slab is reallocated with sprayed data. Hooks also write through `state->net`, corrupting reused kernel objects.\nA:H - Dereferencing a freed `struct net` and calling through a garbage `nf_hook_entries` reliably oopses or panics the kernel, and is a KASAN-reportable memory-safety violation that panics on hardened configurations. Any such kernel crash is scored High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/arp.c" ], "versions": [ { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "10f555e3f573d004ae9d89b3276abb58c4ede5c3", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "307cd1e2d3cb1cbc6c40c679cada6d7168b18431", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "d9366ac2f956a1948b68c0500f84a3462ff2ed8a", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "f189654459423d4d48bef2d120b4bfba559e6039", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "e9f4dee534eb1b225b0a120395ad9bc2afe164d3", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "01d1b5c9abcaff29a43f1d17a19c33eec92c7dbe", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "2c331718d3389b6c5f6855078ab7171849e016bd", "status": "affected", "versionType": "git" }, { "version": "29a26a56803855a79dbd028cd61abee56237d6e5", "lessThan": "a42b69f692165ec39db42d595f4f65a4c8f42e44", "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/ipv4/arp.c" ], "versions": [ { "version": "4.4", "status": "affected" }, { "version": "0", "lessThan": "4.4", "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": "4.4", "versionEndExcluding": "5.4.291" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.6.79" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.12.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.13.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/10f555e3f573d004ae9d89b3276abb58c4ede5c3" }, { "url": "https://git.kernel.org/stable/c/307cd1e2d3cb1cbc6c40c679cada6d7168b18431" }, { "url": "https://git.kernel.org/stable/c/d9366ac2f956a1948b68c0500f84a3462ff2ed8a" }, { "url": "https://git.kernel.org/stable/c/f189654459423d4d48bef2d120b4bfba559e6039" }, { "url": "https://git.kernel.org/stable/c/e9f4dee534eb1b225b0a120395ad9bc2afe164d3" }, { "url": "https://git.kernel.org/stable/c/01d1b5c9abcaff29a43f1d17a19c33eec92c7dbe" }, { "url": "https://git.kernel.org/stable/c/2c331718d3389b6c5f6855078ab7171849e016bd" }, { "url": "https://git.kernel.org/stable/c/a42b69f692165ec39db42d595f4f65a4c8f42e44" } ], "title": "arp: use RCU protection in arp_xmit()", "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-2025-21762", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-27T17:57:30.024595Z" } } } ], "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": "2025-02-27T18:02:27.083Z" } }, { "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": "2025-11-03T19:37:11.540Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T12:03:43.118Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - BIOS", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "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" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-503939.html" } ] } ] } }