{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-05T11:12:32.361","vulnerabilities":[{"cve":{"id":"CVE-2021-47515","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-05-24T15:15:12.937","lastModified":"2025-09-24T19:37:09.340","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nseg6: fix the iif in the IPv6 socket control block\n\nWhen an IPv4 packet is received, the ip_rcv_core(...) sets the receiving\ninterface index into the IPv4 socket control block (v5.16-rc4,\nnet/ipv4/ip_input.c line 510):\n\n    IPCB(skb)->iif = skb->skb_iif;\n\nIf that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH\nheader, the seg6_do_srh_encap(...) performs the required encapsulation.\nIn this case, the seg6_do_srh_encap function clears the IPv6 socket control\nblock (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163):\n\n    memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));\n\nThe memset(...) was introduced in commit ef489749aae5 (\"ipv6: sr: clear\nIP6CB(skb) on SRH ip4ip6 encapsulation\") a long time ago (2019-01-29).\n\nSince the IPv6 socket control block and the IPv4 socket control block share\nthe same memory area (skb->cb), the receiving interface index info is lost\n(IP6CB(skb)->iif is set to zero).\n\nAs a side effect, that condition triggers a NULL pointer dereference if\ncommit 0857d6f8c759 (\"ipv6: When forwarding count rx stats on the orig\nnetdev\") is applied.\n\nTo fix that issue, we set the IP6CB(skb)->iif with the index of the\nreceiving interface once again."},{"lang":"es","value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: seg6: corrige el iif en el bloque de control del socket IPv6 Cuando se recibe un paquete IPv4, ip_rcv_core(...) establece el índice de la interfaz de recepción en el bloque de control del socket IPv4 (v5 .16-rc4, net/ipv4/ip_input.c línea 510): IPCB(skb)->iif = skb->skb_iif; Si ese paquete IPv4 debe encapsularse en un encabezado IPv6+SRH externo, seg6_do_srh_encap(...) realiza la encapsulación requerida. En este caso, la función seg6_do_srh_encap borra el bloque de control del socket IPv6 (v5.16-rc4 net/ipv6/seg6_iptunnel.c línea 163): memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); El memset(...) se introdujo en El commit ef489749aae5 (\"ipv6: sr: clear IP6CB(skb) en la encapsulación SRH ip4ip6\") hace mucho tiempo (29 de enero de 2019). Dado que el bloque de control del socket IPv6 y el bloque de control del socket IPv4 comparten la misma área de memoria (skb->cb), la información del índice de la interfaz de recepción se pierde (IP6CB(skb)->iif se establece en cero). Como efecto secundario, esa condición desencadena una desreferencia del puntero NULL si se aplica el commit 0857d6f8c759 (\"ipv6: al reenviar estadísticas de recuento de rx en el netdev original\"). Para solucionar ese problema, configuramos IP6CB(skb)->iif con el índice de la interfaz de recepción una vez más."}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-476"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.98","versionEndExcluding":"4.14.258","matchCriteriaId":"72C9A7C8-757B-4EFB-AC4E-B383EFFEF45C"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.20","versionEndExcluding":"4.19.221","matchCriteriaId":"9F887262-DA38-45C9-BED5-4D65E50DB9C0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20.7","versionEndExcluding":"5.0","matchCriteriaId":"232F87BF-8F17-4BEB-80A0-49489CB86DDA"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0.1","versionEndExcluding":"5.4.165","matchCriteriaId":"A29CBCD8-CCB1-42FD-BFC8-FD77C4D2FD57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.85","matchCriteriaId":"D9668578-08F7-4694-A86F-FCE448387A79"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.8","matchCriteriaId":"6664ACE2-F748-4AE5-B98B-58803B0B2C3E"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.0:-:*:*:*:*:*:*","matchCriteriaId":"1D0FE595-0CFE-4491-808B-CEF691CE7B0A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.0:rc6:*:*:*:*:*:*","matchCriteriaId":"FDF49B77-4688-4908-9239-89B729456D22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.0:rc7:*:*:*:*:*:*","matchCriteriaId":"77F342FB-3D7B-4EAE-BF8B-57B7B860BAFD"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.0:rc8:*:*:*:*:*:*","matchCriteriaId":"47D61679-6515-4E18-83C7-A71982CCD83C"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*","matchCriteriaId":"357AA433-37E8-4323-BFB2-3038D6E4B414"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*","matchCriteriaId":"A73429BA-C2D9-4D0C-A75F-06A1CA8B3983"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*","matchCriteriaId":"F621B5E3-E99D-49E7-90B9-EC3B77C95383"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*","matchCriteriaId":"F7BFDCAA-1650-49AA-8462-407DD593F94F"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/6431e71093f3da586a00c6d931481ffb0dc2db0e","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/666521b3852d2b2f52d570f9122b1e4b50d96831","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/ae68d93354e5bf5191ee673982251864ea24dd5c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/b16d412e5f79734033df04e97d7ea2f50a8e9fe3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/ef8804e47c0a44ae106ead1740408af5ea6c6ee9","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/6431e71093f3da586a00c6d931481ffb0dc2db0e","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/666521b3852d2b2f52d570f9122b1e4b50d96831","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/98adb2bbfa407c9290bda299d4c6f7a1c4ebd5e1","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/ae68d93354e5bf5191ee673982251864ea24dd5c","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/b16d412e5f79734033df04e97d7ea2f50a8e9fe3","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/ef8804e47c0a44ae106ead1740408af5ea6c6ee9","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]}]}}]}