{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47307", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T13:27:52.133Z", "datePublished": "2024-05-21T14:35:26.667Z", "dateUpdated": "2026-08-05T08:47:11.403Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:11.403Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: prevent NULL deref in cifs_compose_mount_options()\n\nThe optional @ref parameter might contain an NULL node_name, so\nprevent dereferencing it in cifs_compose_mount_options().\n\nAddresses-Coverity: 1476408 (\"Explicit null dereferenced\")" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The NULL deref is in CIFS client DFS referral handling (cifs_compose_mount_options via expand_dfs_referral/do_dfs_failover in cifs_mount), which processes attacker-controlled referral data from a remote SMB/DFS peer over the network, matching other malicious-server CIFS client scores.\nAC:L - Once the client mounts or chases DFS against a referral with a NULL node_name, cifs_build_devname(ref->node_name) deterministically faults with no race or other condition outside the attacker's influence.\nPR:N - The attacker is the malicious or compromised SMB/DFS server and needs no privileges or credentials on the victim host; referral processing runs as part of normal client mount/DFS handling.\nUI:N - In the worst reasonable deployment (fstab/autofs/cifsroot DFS mounts, or automounted DFS junctions under an already-mounted root that re-enter cifs_mount), mount-time referral expansion runs without an exploit-time interactive victim action.\nS:U - A kernel oops in the host CIFS client stays within the same OS security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:N - This is a pure NULL pointer dereference of ref->node_name with no out-of-bounds read, UAF, or other information-disclosure primitive.\nI:N - The defect only crashes on NULL dereference in cifs_build_devname; it does not corrupt memory or provide a write or code-execution primitive.\nA:H - Dereferencing NULL node_name causes a kernel oops/panic during DFS mount option composition, fully denying availability and repeatable on subsequent mounts/referral chases." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/cifs/cifs_dfs_ref.c" ], "versions": [ { "version": "2c55608f28444c3f33b10312881384c470ceed56", "lessThan": "f7d1fa65e74263d11f90ddd33b4d4cd905a93759", "status": "affected", "versionType": "git" }, { "version": "2c55608f28444c3f33b10312881384c470ceed56", "lessThan": "e58c162789becede894d3e94c0ce6695a2ef5796", "status": "affected", "versionType": "git" }, { "version": "2c55608f28444c3f33b10312881384c470ceed56", "lessThan": "ae3d181f4e912f51af7776ea165f199b16fc165d", "status": "affected", "versionType": "git" }, { "version": "2c55608f28444c3f33b10312881384c470ceed56", "lessThan": "03313d1c3a2f086bb60920607ab79ac8f8578306", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/cifs/cifs_dfs_ref.c" ], "versions": [ { "version": "2.6.28", "status": "affected" }, { "version": "0", "lessThan": "2.6.28", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.135", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.53", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13.5", "lessThanOrEqual": "5.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.14", "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": "2.6.28", "versionEndExcluding": "5.4.135" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "5.10.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "5.13.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "5.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f7d1fa65e74263d11f90ddd33b4d4cd905a93759" }, { "url": "https://git.kernel.org/stable/c/e58c162789becede894d3e94c0ce6695a2ef5796" }, { "url": "https://git.kernel.org/stable/c/ae3d181f4e912f51af7776ea165f199b16fc165d" }, { "url": "https://git.kernel.org/stable/c/03313d1c3a2f086bb60920607ab79ac8f8578306" } ], "title": "cifs: prevent NULL deref in cifs_compose_mount_options()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-12T15:23:12.230114Z", "id": "CVE-2021-47307", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-12T15:23:18.690Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:32:08.503Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/f7d1fa65e74263d11f90ddd33b4d4cd905a93759", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/e58c162789becede894d3e94c0ce6695a2ef5796", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/ae3d181f4e912f51af7776ea165f199b16fc165d", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/03313d1c3a2f086bb60920607ab79ac8f8578306", "tags": [ "x_transferred" ] } ] } ] } }