{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47010","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-02-27T18:42:55.953Z","datePublished":"2024-02-28T08:13:29.051Z","dateUpdated":"2026-05-11T13:46:12.794Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T13:46:12.794Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Only allow init netns to set default tcp cong to a restricted algo\n\ntcp_set_default_congestion_control() is netns-safe in that it writes\nto &net->ipv4.tcp_congestion_control, but it also sets\nca->flags |= TCP_CONG_NON_RESTRICTED which is not namespaced.\nThis has the unintended side-effect of changing the global\nnet.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it\nis read-only: 97684f0970f6 (\"net: Make tcp_allowed_congestion_control\nreadonly in non-init netns\")\n\nResolve this netns \"leak\" by only allowing the init netns to set the\ndefault algorithm to one that is restricted. This restriction could be\nremoved if tcp_allowed_congestion_control were namespace-ified in the\nfuture.\n\nThis bug was uncovered with\nhttps://github.com/JonathonReinhart/linux-netns-sysctl-verify"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/tcp_cong.c"],"versions":[{"version":"6670e152447732ba90626f36dfc015a13fbf150e","lessThan":"992de06308d9a9584d59b96d294ac676f924e437","status":"affected","versionType":"git"},{"version":"6670e152447732ba90626f36dfc015a13fbf150e","lessThan":"9884f745108f7d25b189bbcd6754e284fb29ab68","status":"affected","versionType":"git"},{"version":"6670e152447732ba90626f36dfc015a13fbf150e","lessThan":"6c1ea8bee75df8fe2184a50fcd0f70bf82986f42","status":"affected","versionType":"git"},{"version":"6670e152447732ba90626f36dfc015a13fbf150e","lessThan":"efe1532a6e1a8e3c343d04fff510f0ed80328f9c","status":"affected","versionType":"git"},{"version":"6670e152447732ba90626f36dfc015a13fbf150e","lessThan":"e7d7bedd507bb732e600403b7a96f9fe48d0ca31","status":"affected","versionType":"git"},{"version":"6670e152447732ba90626f36dfc015a13fbf150e","lessThan":"8d432592f30fcc34ef5a10aac4887b4897884493","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/tcp_cong.c"],"versions":[{"version":"4.15","status":"affected"},{"version":"0","lessThan":"4.15","status":"unaffected","versionType":"semver"},{"version":"4.19.191","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.119","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.37","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.11.21","lessThanOrEqual":"5.11.*","status":"unaffected","versionType":"semver"},{"version":"5.12.4","lessThanOrEqual":"5.12.*","status":"unaffected","versionType":"semver"},{"version":"5.13","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":"4.15","versionEndExcluding":"4.19.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.4.119"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.10.37"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.11.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.12.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.13"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/992de06308d9a9584d59b96d294ac676f924e437"},{"url":"https://git.kernel.org/stable/c/9884f745108f7d25b189bbcd6754e284fb29ab68"},{"url":"https://git.kernel.org/stable/c/6c1ea8bee75df8fe2184a50fcd0f70bf82986f42"},{"url":"https://git.kernel.org/stable/c/efe1532a6e1a8e3c343d04fff510f0ed80328f9c"},{"url":"https://git.kernel.org/stable/c/e7d7bedd507bb732e600403b7a96f9fe48d0ca31"},{"url":"https://git.kernel.org/stable/c/8d432592f30fcc34ef5a10aac4887b4897884493"}],"title":"net: Only allow init netns to set default tcp cong to a restricted algo","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:24:39.534Z"},"title":"CVE Program 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