{"id":"CVE-2023-53680","state":"PUBLISHED","title":"NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL\n\nOPDESC() simply indexes into nfsd4_ops[] by the op's operation\nnumber, without range checking that value. It assumes callers are\ncareful to avoid calling it with an out-of-bounds opnum value.\n\nnfsd4_decode_compound() is not so careful, and can invoke OPDESC()\nwith opnum set to OP_ILLEGAL, which is 10044 -- well beyond the end\nof nfsd4_ops[].","publishedAt":"2025-10-07T15:21:34.626Z","updatedAt":"2026-10-15T21:41:33.489Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"50827896c365e0f6c8b55ed56d444dafd87c92c5","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"a64160124d5a078be0c380b1e8a0bad2d040d3a1","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"ffcbcf087581ae68ddc0a21460f7ecd4315bdd0e","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"f352c41fa718482979e7e6b71b4da2b718e381cc","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"804d8e0a6e54427268790472781e03bc243f4ee3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4xdr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.14","versionType":"semver"},{"version":"5.10.220","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.107","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.24","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.11","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4xdr.c"]}],"references":["https://git.kernel.org/stable/c/50827896c365e0f6c8b55ed56d444dafd87c92c5","https://git.kernel.org/stable/c/a64160124d5a078be0c380b1e8a0bad2d040d3a1","https://git.kernel.org/stable/c/ffcbcf087581ae68ddc0a21460f7ecd4315bdd0e","https://git.kernel.org/stable/c/f352c41fa718482979e7e6b71b4da2b718e381cc","https://git.kernel.org/stable/c/804d8e0a6e54427268790472781e03bc243f4ee3"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53680.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53680","state":"PUBLISHED","datePublished":"2025-10-07T15:21:34.626Z","dateUpdated":"2026-10-15T21:41:33.489Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-10-07T15:16:59.664Z"},"containers":{"cna":{"title":"NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL\n\nOPDESC() simply indexes into nfsd4_ops[] by the op's operation\nnumber, without range checking that value. It assumes callers are\ncareful to avoid calling it with an out-of-bounds opnum value.\n\nnfsd4_decode_compound() is not so careful, and can invoke OPDESC()\nwith opnum set to OP_ILLEGAL, which is 10044 -- well beyond the end\nof nfsd4_ops[]."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"50827896c365e0f6c8b55ed56d444dafd87c92c5","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"a64160124d5a078be0c380b1e8a0bad2d040d3a1","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"ffcbcf087581ae68ddc0a21460f7ecd4315bdd0e","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"f352c41fa718482979e7e6b71b4da2b718e381cc","versionType":"git"},{"version":"f4f9ef4a1b0a1ca80b152e28e176d69515bdf7e8","status":"affected","lessThan":"804d8e0a6e54427268790472781e03bc243f4ee3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4xdr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.14","versionType":"semver"},{"version":"5.10.220","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.107","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.24","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.11","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4xdr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/50827896c365e0f6c8b55ed56d444dafd87c92c5"},{"url":"https://git.kernel.org/stable/c/a64160124d5a078be0c380b1e8a0bad2d040d3a1"},{"url":"https://git.kernel.org/stable/c/ffcbcf087581ae68ddc0a21460f7ecd4315bdd0e"},{"url":"https://git.kernel.org/stable/c/f352c41fa718482979e7e6b71b4da2b718e381cc"},{"url":"https://git.kernel.org/stable/c/804d8e0a6e54427268790472781e03bc243f4ee3"}],"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 defect is in nfsd's NFSv4 COMPOUND XDR decoder, driven directly by bytes a remote client sends to TCP/2049. Any host able to reach the NFS server can supply the malformed opnum.\nAC:L - Triggering requires only a single COMPOUND request carrying an opnum outside the legal range for the minorversion (e.g. 0, 1, 2, or anything above LAST_NFS42_OP); it is deterministic with no race, timing, or memory-layout dependency.\nPR:N - nfsd4_decode_compound() runs during RPC argument decode, before any export permission, filehandle, or NFSv4 state/authorization check in nfsd4_proc_compound(); with the default AUTH_SYS flavor no principal is authenticated, so an unauthenticated network peer reaches this code.\nUI:N - The attacker sends the malformed COMPOUND unilaterally; nothing is required of any local user or administrator on the server.\nS:U - The out-of-bounds pointer and any resulting fault stay within the kernel's own security authority on the NFS server, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:N - Nothing read from the out-of-bounds address is ever encoded into the NFS reply — the descriptor fields are only tested as flags or used as a call target — and the offset is a hardcoded constant the attacker cannot steer, so no information is disclosed to the attacker.\nI:N - The bug only forms and stores an out-of-bounds read pointer; no attacker-controlled data is written anywhere and no kernel memory is modified.\nA:H - The wild pointer points roughly 550 KB past a const array in nfsd's module mapping, and any dereference of it (e.g. the indirect call OPDESC(op)->op_rsize_bop() in nfsd4_max_reply(), which is protected only by an easily-missed open-coded OP_ILLEGAL check) faults in an nfsd kthread and takes the NFS service down. A remote unauthenticated attacker can repeat the request at will, so the availability impact is scored High."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T09:15:31.911Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.10.220"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.15.107"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.1.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.2.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2023-53680","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-15T21:36:29.078436Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T21:41:33.489Z"}}]}}}