{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2021-46908", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-25T13:45:52.718Z", "datePublished": "2024-02-27T06:53:49.541Z", "dateUpdated": "2026-08-05T08:44:59.893Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:44:59.893Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use correct permission flag for mixed signed bounds arithmetic\n\nWe forbid adding unknown scalars with mixed signed bounds due to the\nspectre v1 masking mitigation. Hence this also needs bypass_spec_v1\nflag instead of allow_ptr_leaks."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The vulnerable code is in the BPF verifier (adjust_ptr_min_max_vals), reached only via the local bpf() syscall when loading a program (e.g. SOCKET_FILTER), not via network packet processing.\nAC:L - An attacker can reliably craft and load a BPF program with mixed signed-bounds pointer arithmetic on PTR_TO_MAP_VALUE; no race or external environmental condition beyond the attacker's control is required to reach the buggy check. Unprivileged users can load BPF_PROG_TYPE_SOCKET_FILTER/CGROUP_SKB when kernel.unprivileged_bpf_disabled is 0 (upstream default throughout the 5.8\u20135.11 affected range), which exercises this verifier path without CAP_BPF or CAP_PERFMON. An attacker can reliably craft and load a BPF program with mixed signed-bounds pointer arithmetic on PTR_TO_MAP_VALUE; no race or external environmental condition beyond the attacker's control is required to reach the buggy check.\nPR:L - Unprivileged users can load BPF_PROG_TYPE_SOCKET_FILTER/CGROUP_SKB when kernel.unprivileged_bpf_disabled is 0 (upstream default throughout the 5.8\u20135.11 affected range), which exercises this verifier path without CAP_BPF or CAP_PERFMON.\nUI:N - Exploitation requires only the attacker loading their own BPF program; no victim action is needed.\nS:U - Impact stays within the kernel's security authority (local speculative disclosure of kernel memory); this is not a VM/IOMMU/sandbox boundary crossing.\nC:H - The check exists specifically for Spectre v1 masking of map-value pointer arithmetic; bypassing it enables speculative out-of-bounds access that can disclose arbitrary kernel memory via side channels, matching other BPF Spectre CVEs.\nI:N - This is a speculative-execution mitigation gap; architectural verifier bounds still apply and speculative effects do not commit writes, so integrity is not impacted.\nA:H - Same-series BPF Spectre sanitation bugs (e.g. CVE-2020-27171) and existing assessments of this CVE treat failed/incorrect ALU sanitation as potentially crashing the kernel; under the overestimate rule A:H is the higher-severity choice."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/verifier.c"], "versions": [{"version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "lessThan": "4f3ff11204eac0ee23acf64deecb3bad7b0db0c6", "status": "affected", "versionType": "git"}, {"version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "lessThan": "4ccdc6c6cae38b91c871293fb0ed8c6845a61b51", "status": "affected", "versionType": "git"}, {"version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "lessThan": "9601148392520e2e134936e76788fc2a6371e7be", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/verifier.c"], "versions": [{"version": "5.8", "status": "affected"}, {"version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.32", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.11.16", "lessThanOrEqual": "5.11.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.12", "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": "5.8", "versionEndExcluding": "5.10.32"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "5.11.16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "5.12"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6"}, {"url": "https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51"}, {"url": "https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be"}], "title": "bpf: Use correct permission flag for mixed signed bounds arithmetic", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-46908", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-02-27T15:41:34.586719Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:13:12.609Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:43.036Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:43.036Z"}}, {"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-46908", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-02-27T15:41:34.586719Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-05-23T19:01:13.366Z"}, "title": "CISA ADP Vulnrichment"}], "cna": {"title": "bpf: Use correct permission flag for mixed signed bounds arithmetic", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.1, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - The vulnerable code is in the BPF verifier (adjust_ptr_min_max_vals), reached only via the local bpf() syscall when loading a program (e.g. SOCKET_FILTER), not via network packet processing.\nAC:L - An attacker can reliably craft and load a BPF program with mixed signed-bounds pointer arithmetic on PTR_TO_MAP_VALUE; no race or external environmental condition beyond the attacker's control is required to reach the buggy check. Unprivileged users can load BPF_PROG_TYPE_SOCKET_FILTER/CGROUP_SKB when kernel.unprivileged_bpf_disabled is 0 (upstream default throughout the 5.8\u20135.11 affected range), which exercises this verifier path without CAP_BPF or CAP_PERFMON. An attacker can reliably craft and load a BPF program with mixed signed-bounds pointer arithmetic on PTR_TO_MAP_VALUE; no race or external environmental condition beyond the attacker's control is required to reach the buggy check.\nPR:L - Unprivileged users can load BPF_PROG_TYPE_SOCKET_FILTER/CGROUP_SKB when kernel.unprivileged_bpf_disabled is 0 (upstream default throughout the 5.8\u20135.11 affected range), which exercises this verifier path without CAP_BPF or CAP_PERFMON.\nUI:N - Exploitation requires only the attacker loading their own BPF program; no victim action is needed.\nS:U - Impact stays within the kernel's security authority (local speculative disclosure of kernel memory); this is not a VM/IOMMU/sandbox boundary crossing.\nC:H - The check exists specifically for Spectre v1 masking of map-value pointer arithmetic; bypassing it enables speculative out-of-bounds access that can disclose arbitrary kernel memory via side channels, matching other BPF Spectre CVEs.\nI:N - This is a speculative-execution mitigation gap; architectural verifier bounds still apply and speculative effects do not commit writes, so integrity is not impacted.\nA:H - Same-series BPF Spectre sanitation bugs (e.g. CVE-2020-27171) and existing assessments of this CVE treat failed/incorrect ALU sanitation as potentially crashing the kernel; under the overestimate rule A:H is the higher-severity choice."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "lessThan": "4f3ff11204eac0ee23acf64deecb3bad7b0db0c6", "versionType": "git"}, {"status": "affected", "version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "lessThan": "4ccdc6c6cae38b91c871293fb0ed8c6845a61b51", "versionType": "git"}, {"status": "affected", "version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "lessThan": "9601148392520e2e134936e76788fc2a6371e7be", "versionType": "git"}], "programFiles": ["kernel/bpf/verifier.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.8"}, {"status": "unaffected", "version": "0", "lessThan": "5.8", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.32", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.11.16", "versionType": "semver", "lessThanOrEqual": "5.11.*"}, {"status": "unaffected", "version": "5.12", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["kernel/bpf/verifier.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6"}, {"url": "https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51"}, {"url": "https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use correct permission flag for mixed signed bounds arithmetic\n\nWe forbid adding unknown scalars with mixed signed bounds due to the\nspectre v1 masking mitigation. Hence this also needs bypass_spec_v1\nflag instead of allow_ptr_leaks."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.32", "versionStartIncluding": "5.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.11.16", "versionStartIncluding": "5.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.12", "versionStartIncluding": "5.8"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:44:59.893Z"}}}, "cveMetadata": {"cveId": "CVE-2021-46908", "state": "PUBLISHED", "dateUpdated": "2026-08-05T08:44:59.893Z", "dateReserved": "2024-02-25T13:45:52.718Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-02-27T06:53:49.541Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/bpf/verifier.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "4f3ff11204eac0ee23acf64deecb3bad7b0db0c6", "status": "affected", "version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "versionType": "git"}, {"lessThan": "4ccdc6c6cae38b91c871293fb0ed8c6845a61b51", "status": "affected", "version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "versionType": "git"}, {"lessThan": "9601148392520e2e134936e76788fc2a6371e7be", "status": "affected", "version": "2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/bpf/verifier.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.8"}, {"lessThan": "5.8", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.32", "versionType": "semver"}, {"lessThanOrEqual": "5.11.*", "status": "unaffected", "version": "5.11.16", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "5.12", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "DE87B38C-0350-471A-8830-58E1E02F7E2E", "versionEndExcluding": "5.10.32", "versionStartIncluding": "5.8.0", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "3C5242B9-B5BD-4578-AD66-69DF59D54A14", "versionEndExcluding": "5.11.16", "versionStartIncluding": "5.11.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use correct permission flag for mixed signed bounds arithmetic\n\nWe forbid adding unknown scalars with mixed signed bounds due to the\nspectre v1 masking mitigation. Hence this also needs bypass_spec_v1\nflag instead of allow_ptr_leaks."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: bpf: use el indicador de permiso correcto para aritm\u00e9tica de los l\u00edmites con signo mixto Prohibimos agregar escalares desconocidos con l\u00edmites con signo mixto debido a la mitigaci\u00f3n de enmascaramiento de Spectre v1. Por lo tanto, esto tambi\u00e9n necesita el indicador bypass_spec_v1 en lugar de enable_ptr_leaks."}], "id": "CVE-2021-46908", "lastModified": "2026-08-04T10:16:35.773", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "[email protected]", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-46908", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-02-27T15:41:34.586719Z", "version": "2.0.3"}}]}, "published": "2024-02-27T07:15:06.977", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "[email protected]", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: unknown scalars with mixed signed bounds masking mitigation", "id": "2266407", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2266407"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:H", "status": "draft"}, "cwe": "CWE-20", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nbpf: Use correct permission flag for mixed signed bounds arithmetic\nWe forbid adding unknown scalars with mixed signed bounds due to the\nspectre v1 masking mitigation. Hence this also needs bypass_spec_v1\nflag instead of allow_ptr_leaks.", "A flaw was found in the Linux Kernel. Adding unknown scalars with mixed signed bounds are forbidden due to the spectre v1 masking mitigation. Therefore, this needs the bypass_spec_v1 flag instead of allow_ptr_leaks."], "name": "CVE-2021-46908", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-02-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-46908\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-46908\nhttps://git.kernel.org/stable/c/4ccdc6c6cae38b91c871293fb0ed8c6845a61b51\nhttps://git.kernel.org/stable/c/4f3ff11204eac0ee23acf64deecb3bad7b0db0c6\nhttps://git.kernel.org/stable/c/9601148392520e2e134936e76788fc2a6371e7be"], "threat_severity": "Moderate"}

{}