{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53338", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-09-16T16:08:59.565Z", "datePublished": "2025-09-17T14:56:32.302Z", "dateUpdated": "2026-08-05T09:13:35.491Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:13:35.491Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlwt: Fix return values of BPF xmit ops\n\nBPF encap ops can return different types of positive values, such like\nNET_RX_DROP, NET_XMIT_CN, NETDEV_TX_BUSY, and so on, from function\nskb_do_redirect and bpf_lwt_xmit_reroute. At the xmit hook, such return\nvalues would be treated implicitly as LWTUNNEL_XMIT_CONTINUE in\nip(6)_finish_output2. When this happens, skbs that have been freed would\ncontinue to the neighbor subsystem, causing use-after-free bug and\nkernel crashes.\n\nTo fix the incorrect behavior, skb_do_redirect return values can be\nsimply discarded, the same as tc-egress behavior. On the other hand,\nbpf_lwt_xmit_reroute returns useful errors to local senders, e.g. PMTU\ninformation. Thus convert its return values to avoid the conflict with\nLWTUNNEL_XMIT_CONTINUE." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - On hosts with LWT BPF xmit routes (e.g. edge/CDN forwarders), remote packets that are forwarded or that induce local replies reach ip(6)_finish_output2 → lwtunnel_xmit → bpf_xmit, so an unauthenticated network peer drives the vulnerable path.\nAC:L - LWT BPF xmit programs routinely return BPF_REDIRECT or BPF_LWT_REROUTE; skb_do_redirect/dst_output then yield positive NET_XMIT_*/NETDEV_TX_* statuses (e.g. NET_XMIT_CN under load) that the attacker can provoke by sending traffic, with no condition outside their control.\nPR:N - Once an LWT BPF xmit route is configured, no credentials are required—any remote peer whose packets traverse that route reaches the bug; local unprivileged traffic generation likewise needs no elevated privileges.\nUI:N - Exploitation requires only attacker-generated traffic against an already-configured LWT BPF route; no victim or administrator action is needed at exploit time.\nS:U - The use-after-free and any resulting privilege escalation remain within the host kernel's security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The bug is a use-after-free of a consumed skb that continues into the neighbor subsystem; reclaiming and spraying that object enables arbitrary kernel memory disclosure.\nI:H - The same skb UAF in neigh_output provides heap corruption suitable for arbitrary write and control-flow hijack, i.e. full kernel integrity compromise.\nA:H - Continuing a freed skb into neigh_output reliably causes kernel oops/panic, as documented in the fix and reproduced by the LWT redirect selftests." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/lwt_bpf.c" ], "versions": [ { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "67f8f2bae8e7ac72e09def2b667e44704c4d1ee1", "status": "affected", "versionType": "git" }, { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "a97f221651fcdc891166e9bc270e3d9bfa5a0080", "status": "affected", "versionType": "git" }, { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "e3f647e4b642f9f6d32795a16f92c116c138d2af", "status": "affected", "versionType": "git" }, { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "065d5f17096ec9161180e2c890afdff4dc6125f2", "status": "affected", "versionType": "git" }, { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "d68c17402442f5f494a2c3ebde5cb82f6aa9160a", "status": "affected", "versionType": "git" }, { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "65583f9e070db7bece20710cfa2e3daeb0b831d9", "status": "affected", "versionType": "git" }, { "version": "3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2", "lessThan": "29b22badb7a84b783e3a4fffca16f7768fb31205", "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/lwt_bpf.c" ], "versions": [ { "version": "4.10", "status": "affected" }, { "version": "0", "lessThan": "4.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.257", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.195", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.132", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.53", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.16", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5.3", "lessThanOrEqual": "6.5.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6", "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": "4.10", "versionEndExcluding": "5.4.257" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.10.195" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.15.132" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.1.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.4.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.5.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/67f8f2bae8e7ac72e09def2b667e44704c4d1ee1" }, { "url": "https://git.kernel.org/stable/c/a97f221651fcdc891166e9bc270e3d9bfa5a0080" }, { "url": "https://git.kernel.org/stable/c/e3f647e4b642f9f6d32795a16f92c116c138d2af" }, { "url": "https://git.kernel.org/stable/c/065d5f17096ec9161180e2c890afdff4dc6125f2" }, { "url": "https://git.kernel.org/stable/c/d68c17402442f5f494a2c3ebde5cb82f6aa9160a" }, { "url": "https://git.kernel.org/stable/c/65583f9e070db7bece20710cfa2e3daeb0b831d9" }, { "url": "https://git.kernel.org/stable/c/29b22badb7a84b783e3a4fffca16f7768fb31205" } ], "title": "lwt: Fix return values of BPF xmit ops", "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-2023-53338", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-01-14T18:38:11.999922Z" } } } ], "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": "2026-01-14T18:43:01.329Z" } } ] } }