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CVE-2021-47670 (GCVE-0-2021-47670)

Vulnerability from cvelistv5 – Published: 2025-04-17 18:01 – Updated: 2026-08-05 08:48
VLAI
Title
can: peak_usb: fix use after free bugs
Summary
In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: fix use after free bugs After calling peak_usb_netif_rx_ni(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is accessed after the peak_usb_netif_rx_ni(). Reordering the lines solves the issue.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-04-17 18:17 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 0a25e1f4f18566b750ebd3ae995af64e23111e63 , < 5408824636fa0dfedb9ecb0d94abd573131bfbbe (git)
Affected: 0a25e1f4f18566b750ebd3ae995af64e23111e63 , < ddd1416f44130377798c1430b76503513b7497c2 (git)
Affected: 0a25e1f4f18566b750ebd3ae995af64e23111e63 , < ec939c13c3fff2114479769c8380b7f1a54feca9 (git)
Affected: 0a25e1f4f18566b750ebd3ae995af64e23111e63 , < 50aca891d7a554db0901b245167cd653d73aaa71 (git)
guessed Create a notification for this product.
Linux Linux Affected: 4.0
Unaffected: 0 , < 4.0 (semver)
Unaffected: 4.19.171 , ≤ 4.19.* (semver)
Unaffected: 5.4.93 , ≤ 5.4.* (semver)
Unaffected: 5.10.11 , ≤ 5.10.* (semver)
Unaffected: 5.11 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.8, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-47670\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-04-17T18:17:46.529671Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-416\", \"description\": \"CWE-416 Use After Free\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-04-17T18:17:48.474Z\"}}], \"cna\": {\"title\": \"can: peak_usb: fix use after free bugs\", \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 8.8, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"AV:A - The UAF is in pcan_usb_fd_decode_canmsg/decode_status on the USB bulk RX path that delivers CAN/CAN-FD frames from a PEAK USB FD adapter. In the highest realistic deployment (automotive/industrial host with the adapter already attached and the CAN netdev up), an attacker on the shared CAN bus can send frames that the adapter forwards into this decode path, which is an adjacent-segment attack analogous to Bluetooth/WiFi rather than a pure physical plug-in.\\nAC:L - Any received CAN frame or status message that takes the decode path calls peak_usb_netif_rx() and then dereferences the can_frame alias; the attacker fully controls frame generation on the bus and does not depend on an uncontrollable race or rare memory layout to trigger the use-after-free.\\nPR:N - CAN-bus peers need no host account or capability; once the PEAK interface is up in normal operation, URB completion runs in kernel context with no authentication of on-bus traffic.\\nUI:N - No separate victim action is required beyond the already-deployed adapter and up interface; on-bus frames are processed automatically by peak_usb_read_bulk_callback \\u2192 pcan_usb_fd_decode_buf.\\nS:U - Impact is confined to the same host kernel that owns the peak_usb driver and skb allocator; this is ordinary kernel memory corruption, not a VM escape, IOMMU bypass, or other cross-authority boundary crossing.\\nC:H - This is a use-after-free of an sk_buff/can_frame after ownership transfer to netif_rx; UAF of heap objects enables reclaim and disclosure of freed object contents, so confidentiality is scored High.\\nI:H - The same UAF allows heap reuse of the freed skb object and is treated as providing a corruption/write primitive suitable for control-flow hijack under kernel UAF guidance, so integrity is High.\\nA:H - Use-after-free of skb memory after netif_rx can oops/panic when the object is reused or unmapped, and UAF bugs are scored High availability even when not fully exploited for code execution.\"}]}], \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"0a25e1f4f18566b750ebd3ae995af64e23111e63\", \"lessThan\": \"5408824636fa0dfedb9ecb0d94abd573131bfbbe\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"0a25e1f4f18566b750ebd3ae995af64e23111e63\", \"lessThan\": \"ddd1416f44130377798c1430b76503513b7497c2\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"0a25e1f4f18566b750ebd3ae995af64e23111e63\", \"lessThan\": \"ec939c13c3fff2114479769c8380b7f1a54feca9\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"0a25e1f4f18566b750ebd3ae995af64e23111e63\", \"lessThan\": \"50aca891d7a554db0901b245167cd653d73aaa71\", \"versionType\": \"git\"}], \"programFiles\": [\"drivers/net/can/usb/peak_usb/pcan_usb_fd.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"4.0\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"4.0\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"4.19.171\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"4.19.*\"}, {\"status\": \"unaffected\", \"version\": \"5.4.93\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.4.*\"}, {\"status\": \"unaffected\", \"version\": \"5.10.11\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.10.*\"}, {\"status\": \"unaffected\", \"version\": \"5.11\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"drivers/net/can/usb/peak_usb/pcan_usb_fd.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/5408824636fa0dfedb9ecb0d94abd573131bfbbe\"}, {\"url\": \"https://git.kernel.org/stable/c/ddd1416f44130377798c1430b76503513b7497c2\"}, {\"url\": \"https://git.kernel.org/stable/c/ec939c13c3fff2114479769c8380b7f1a54feca9\"}, {\"url\": \"https://git.kernel.org/stable/c/50aca891d7a554db0901b245167cd653d73aaa71\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\ncan: peak_usb: fix use after free bugs\\n\\nAfter calling peak_usb_netif_rx_ni(skb), dereferencing skb is unsafe.\\nEspecially, the can_frame cf which aliases skb memory is accessed\\nafter the peak_usb_netif_rx_ni().\\n\\nReordering the lines solves the issue.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"4.19.171\", \"versionStartIncluding\": \"4.0\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.4.93\", \"versionStartIncluding\": \"4.0\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.10.11\", \"versionStartIncluding\": \"4.0\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.11\", \"versionStartIncluding\": \"4.0\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2026-08-05T08:48:50.364Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-47670\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-05T08:48:50.364Z\", \"dateReserved\": \"2025-04-16T07:16:05.752Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2025-04-17T18:01:30.722Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.