{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47049","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-02-27T18:42:55.971Z","datePublished":"2024-02-28T08:13:52.168Z","dateUpdated":"2026-08-05T08:45:44.180Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:45:44.180Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nDrivers: hv: vmbus: Use after free in __vmbus_open()\n\nThe \"open_info\" variable is added to the &vmbus_connection.chn_msg_list,\nbut the error handling frees \"open_info\" without removing it from the\nlist.  This will result in a use after free.  First remove it from the\nlist, and then free it."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only over the Hyper-V guest VMBus path (__vmbus_open during channel open after a host offer/rescind), which is local hypervisor IPC rather than an IP network or physical bus attack surface.\nAC:L - A malicious Hyper-V host fully controls CHANNELMSG_OFFERCHANNEL and CHANNELMSG_RESCIND_CHANNELOFFER timing relative to guest __vmbus_open(), so it can deterministically hit the rescinded-channel error path after open_info is linked onto chn_msg_list.\nPR:N - No privileges inside the guest are required; rescind/open messages are accepted from the Hyper-V parent over VMBus with no guest authentication, matching the untrusted-host/CoCo threat model used for similar vmbus bugs.\nUI:N - Channel probe/open and rescind handling run automatically in kernel workqueues when the host sends VMBus messages; no victim user action is required.\nS:U - The UAF corrupts guest-kernel heap state (chn_msg_list / vmbus_channel_msginfo) within the same guest OS security authority; it is not a guest-to-host escape.\nC:H - Use-after-free of open_info on a globally walked list enables heap reuse and arbitrary read primitives against kernel memory.\nI:H - The same UAF is exploitable for heap spraying and control-flow hijacking / arbitrary write in the guest kernel.\nA:H - Any subsequent chn_msg_list walk over the dangling entry can oops/panic the guest kernel even without a full exploit."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hv/channel.c"],"versions":[{"version":"6f3d791f300618caf82a2be0c27456edd76d5164","lessThan":"d5c7b42c9f56ca46b286daa537d181bd7f69214f","status":"affected","versionType":"git"},{"version":"6f3d791f300618caf82a2be0c27456edd76d5164","lessThan":"f37dd5d1b5d38a79a4f7b8dd7bbb705505f05560","status":"affected","versionType":"git"},{"version":"6f3d791f300618caf82a2be0c27456edd76d5164","lessThan":"2728f289b3270b0e273292b46c534421a33bbfd5","status":"affected","versionType":"git"},{"version":"6f3d791f300618caf82a2be0c27456edd76d5164","lessThan":"3e9bf43f7f7a46f21ec071cb47be92d0874c48da","status":"affected","versionType":"git"},{"version":"6b32d45bd59982751beb8220e442b40b2706647f","status":"affected","versionType":"git"},{"version":"4.13.9","lessThan":"4.14","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hv/channel.c"],"versions":[{"version":"4.14","status":"affected"},{"version":"0","lessThan":"4.14","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":"4.14","versionEndExcluding":"5.10.37"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.11.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.12.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13.9"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d5c7b42c9f56ca46b286daa537d181bd7f69214f"},{"url":"https://git.kernel.org/stable/c/f37dd5d1b5d38a79a4f7b8dd7bbb705505f05560"},{"url":"https://git.kernel.org/stable/c/2728f289b3270b0e273292b46c534421a33bbfd5"},{"url":"https://git.kernel.org/stable/c/3e9bf43f7f7a46f21ec071cb47be92d0874c48da"}],"title":"Drivers: hv: vmbus: Use after free in __vmbus_open()","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:24:39.572Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/d5c7b42c9f56ca46b286daa537d181bd7f69214f","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/f37dd5d1b5d38a79a4f7b8dd7bbb705505f05560","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/2728f289b3270b0e273292b46c534421a33bbfd5","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/3e9bf43f7f7a46f21ec071cb47be92d0874c48da","tags":["x_transferred"]}]},{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-08-08T18:59:39.474038Z","id":"CVE-2021-47049","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-08-08T18:59:54.282Z"}}]}}