{"id":"CVE-2025-21993","state":"PUBLISHED","title":"iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()\n\nWhen performing an iSCSI boot using IPv6, iscsistart still reads the\n/sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix\nlength is 64, this causes the shift exponent to become negative,\ntriggering a UBSAN warning. As the concept of a subnet mask does not\napply to IPv6, the value is set to ~0 to suppress the warning message.","publishedAt":"2025-04-02T12:53:15.513Z","updatedAt":"2026-05-11T21:10:34.056Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"CISA-ADP"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"a858cd58dea06cf85b142673deea8c5d87f11e70","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"f763c82db8166e28f45b7cc4a5398a7859665940","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"b388e185bfad32bfed6a97a6817f74ca00a4318f","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1c","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"2d1eef248107bdf3d5a69d0fde04c30a79a7bf5d","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"b253660fac5e0e9080d2c95e3a029e1898d49afb","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"c1c6e527470e5eab0b2d57bd073530fbace39eab","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"07e0d99a2f701123ad3104c0f1a1e66bce74d6e5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/iscsi_ibft.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.26","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.26","versionType":"semver"},{"version":"5.4.292","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.236","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.180","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.132","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.84","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.20","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.8","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/iscsi_ibft.c"]}],"references":["https://git.kernel.org/stable/c/a858cd58dea06cf85b142673deea8c5d87f11e70","https://git.kernel.org/stable/c/f763c82db8166e28f45b7cc4a5398a7859665940","https://git.kernel.org/stable/c/b388e185bfad32bfed6a97a6817f74ca00a4318f","https://git.kernel.org/stable/c/9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1c","https://git.kernel.org/stable/c/2d1eef248107bdf3d5a69d0fde04c30a79a7bf5d","https://git.kernel.org/stable/c/b253660fac5e0e9080d2c95e3a029e1898d49afb","https://git.kernel.org/stable/c/c1c6e527470e5eab0b2d57bd073530fbace39eab","https://git.kernel.org/stable/c/07e0d99a2f701123ad3104c0f1a1e66bce74d6e5","https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html","https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/21xxx/CVE-2025-21993.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-21993","state":"PUBLISHED","datePublished":"2025-04-02T12:53:15.513Z","dateUpdated":"2026-05-11T21:10:34.056Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-12-29T08:45:45.801Z"},"containers":{"cna":{"title":"iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()\n\nWhen performing an iSCSI boot using IPv6, iscsistart still reads the\n/sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix\nlength is 64, this causes the shift exponent to become negative,\ntriggering a UBSAN warning. As the concept of a subnet mask does not\napply to IPv6, the value is set to ~0 to suppress the warning message."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"a858cd58dea06cf85b142673deea8c5d87f11e70","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"f763c82db8166e28f45b7cc4a5398a7859665940","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"b388e185bfad32bfed6a97a6817f74ca00a4318f","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1c","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"2d1eef248107bdf3d5a69d0fde04c30a79a7bf5d","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"b253660fac5e0e9080d2c95e3a029e1898d49afb","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"c1c6e527470e5eab0b2d57bd073530fbace39eab","versionType":"git"},{"version":"138fe4e069798d9aa948a5402ff15e58f483ee4e","status":"affected","lessThan":"07e0d99a2f701123ad3104c0f1a1e66bce74d6e5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/iscsi_ibft.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.26","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.26","versionType":"semver"},{"version":"5.4.292","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.236","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.180","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.132","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.84","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.20","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.8","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/iscsi_ibft.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a858cd58dea06cf85b142673deea8c5d87f11e70"},{"url":"https://git.kernel.org/stable/c/f763c82db8166e28f45b7cc4a5398a7859665940"},{"url":"https://git.kernel.org/stable/c/b388e185bfad32bfed6a97a6817f74ca00a4318f"},{"url":"https://git.kernel.org/stable/c/9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1c"},{"url":"https://git.kernel.org/stable/c/2d1eef248107bdf3d5a69d0fde04c30a79a7bf5d"},{"url":"https://git.kernel.org/stable/c/b253660fac5e0e9080d2c95e3a029e1898d49afb"},{"url":"https://git.kernel.org/stable/c/c1c6e527470e5eab0b2d57bd073530fbace39eab"},{"url":"https://git.kernel.org/stable/c/07e0d99a2f701123ad3104c0f1a1e66bce74d6e5"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:10:34.056Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"5.4.292"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"5.10.236"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"5.15.180"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.1.132"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.6.84"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.12.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.13.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.14"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.1,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2025-10-01T17:13:21.283055Z","id":"CVE-2025-21993","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":"2025-10-01T17:13:24.916Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T19:40:33.731Z"}}]}}}