{"id":"CVE-2021-47478","state":"PUBLISHED","title":"isofs: Fix out of bound access for corrupted isofs image","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nisofs: Fix out of bound access for corrupted isofs image\n\nWhen isofs image is suitably corrupted isofs_read_inode() can read data\nbeyond the end of buffer. Sanity-check the directory entry length before\nusing it.","publishedAt":"2024-05-22T08:19:31.521Z","updatedAt":"2026-08-05T08:47:59.496Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"156ce5bb6cc43a80a743810199defb1dc3f55b7f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9ec33a9b8790c212cc926a88c5e2105f97f3f57e","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"afbd40f425227e661d991757e11cc4db024e761f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b0ddff8d68f2e43857a84dce54c3deab181c8ae1","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6e80e9314f8bb52d9eabe1907698718ff01120f5","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"86d4aedcbc69c0f84551fb70f953c24e396de2d7","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b2fa1f52d22c5455217b294629346ad23a744945","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e7fb722586a2936b37bdff096c095c30ca06404d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e96a1866b40570b5950cda8602c2819189c62a48","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/isofs/inode.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"4.4.292","status":"unaffected","lessThanOrEqual":"4.4.*","versionType":"semver"},{"version":"4.9.290","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.255","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.217","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.159","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.79","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.14.18","status":"unaffected","lessThanOrEqual":"5.14.*","versionType":"semver"},{"version":"5.15.2","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/isofs/inode.c"]}],"references":["https://git.kernel.org/stable/c/156ce5bb6cc43a80a743810199defb1dc3f55b7f","https://git.kernel.org/stable/c/9ec33a9b8790c212cc926a88c5e2105f97f3f57e","https://git.kernel.org/stable/c/afbd40f425227e661d991757e11cc4db024e761f","https://git.kernel.org/stable/c/b0ddff8d68f2e43857a84dce54c3deab181c8ae1","https://git.kernel.org/stable/c/6e80e9314f8bb52d9eabe1907698718ff01120f5","https://git.kernel.org/stable/c/86d4aedcbc69c0f84551fb70f953c24e396de2d7","https://git.kernel.org/stable/c/b2fa1f52d22c5455217b294629346ad23a744945","https://git.kernel.org/stable/c/e7fb722586a2936b37bdff096c095c30ca06404d","https://git.kernel.org/stable/c/e96a1866b40570b5950cda8602c2819189c62a48"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47478.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47478","state":"PUBLISHED","datePublished":"2024-05-22T08:19:31.521Z","dateUpdated":"2026-08-05T08:47:59.496Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-22T06:20:56.200Z"},"containers":{"cna":{"title":"isofs: Fix out of bound access for corrupted isofs image","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nisofs: Fix out of bound access for corrupted isofs image\n\nWhen isofs image is suitably corrupted isofs_read_inode() can read data\nbeyond the end of buffer. Sanity-check the directory entry length before\nusing it."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"156ce5bb6cc43a80a743810199defb1dc3f55b7f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9ec33a9b8790c212cc926a88c5e2105f97f3f57e","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"afbd40f425227e661d991757e11cc4db024e761f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b0ddff8d68f2e43857a84dce54c3deab181c8ae1","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6e80e9314f8bb52d9eabe1907698718ff01120f5","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"86d4aedcbc69c0f84551fb70f953c24e396de2d7","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b2fa1f52d22c5455217b294629346ad23a744945","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e7fb722586a2936b37bdff096c095c30ca06404d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e96a1866b40570b5950cda8602c2819189c62a48","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/isofs/inode.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"4.4.292","status":"unaffected","lessThanOrEqual":"4.4.*","versionType":"semver"},{"version":"4.9.290","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.255","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.217","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.159","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.79","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.14.18","status":"unaffected","lessThanOrEqual":"5.14.*","versionType":"semver"},{"version":"5.15.2","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/isofs/inode.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/156ce5bb6cc43a80a743810199defb1dc3f55b7f"},{"url":"https://git.kernel.org/stable/c/9ec33a9b8790c212cc926a88c5e2105f97f3f57e"},{"url":"https://git.kernel.org/stable/c/afbd40f425227e661d991757e11cc4db024e761f"},{"url":"https://git.kernel.org/stable/c/b0ddff8d68f2e43857a84dce54c3deab181c8ae1"},{"url":"https://git.kernel.org/stable/c/6e80e9314f8bb52d9eabe1907698718ff01120f5"},{"url":"https://git.kernel.org/stable/c/86d4aedcbc69c0f84551fb70f953c24e396de2d7"},{"url":"https://git.kernel.org/stable/c/b2fa1f52d22c5455217b294629346ad23a744945"},{"url":"https://git.kernel.org/stable/c/e7fb722586a2936b37bdff096c095c30ca06404d"},{"url":"https://git.kernel.org/stable/c/e96a1866b40570b5950cda8602c2819189c62a48"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":9.1,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - isofs implements export_operations, and nfsd decodes client filehandles via isofs_fh_to_dentry into isofs_read_inode with attacker-chosen block/offset. A remote NFS client can therefore reach the bug over the network on a host that exports an iso9660 mount.\nAC:L - The attacker fully controls the NFS filehandle block/offset and can aim at a byte near a buffer boundary whose length field is below sizeof(struct iso_directory_record), reliably taking the undersized de_len path. No race or layout outside attacker influence is required.\nPR:N - In the highest-severity reasonable deployment, an iso9660 tree is NFS-exported with unauthenticated or otherwise unprivileged client access (common sec=sys/media-server setups). The remote attacker needs no privileges on the NFS server host.\nUI:N - Once the iso9660 filesystem is exported, the attacker triggers isofs_read_inode by sending NFS requests with a crafted filehandle. No separate victim action such as mounting or opening a file is required at exploit time.\nS:U - The out-of-bounds read occurs in the same kernel authority that runs nfsd/isofs. This is not a VM escape, IOMMU bypass, or other cross-scope boundary violation.\nC:H - With de_len smaller than the directory-record struct, isofs_read_inode reads past a kmalloc(de_len) buffer or past bh->b_data; syzbot reported a KASAN use-after-free read in this path. That over-read can disclose adjacent kernel memory and can also surface through inode fields returned over NFS.\nI:N - The defect is an out-of-bounds read of directory-entry fields into inode metadata, not an out-of-bounds write or other memory-modification primitive. No integrity impact beyond interpreting over-read bytes as ISO metadata is indicated.\nA:H - The same invalid read was shown to fault under KASAN and can oops when it touches freed or unmapped memory beyond the undersized object or buffer_head. A remote client can repeat crafted filehandle lookups to cause a high-impact denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:47:59.496Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.4.292"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.9.290"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.14.255"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.19.217"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.4.159"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.79"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.14.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2024-05-29T18:36:21.366364Z","id":"CVE-2021-47478","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","type":"CWE","lang":"en","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-11-07T15:12:42.793Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/156ce5bb6cc43a80a743810199defb1dc3f55b7f","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9ec33a9b8790c212cc926a88c5e2105f97f3f57e","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/afbd40f425227e661d991757e11cc4db024e761f","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/b0ddff8d68f2e43857a84dce54c3deab181c8ae1","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/6e80e9314f8bb52d9eabe1907698718ff01120f5","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/86d4aedcbc69c0f84551fb70f953c24e396de2d7","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/b2fa1f52d22c5455217b294629346ad23a744945","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/e7fb722586a2936b37bdff096c095c30ca06404d","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/e96a1866b40570b5950cda8602c2819189c62a48","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:39:59.618Z"}}]}}}