Vulnerability-Lookup

FKIE_CVE-2021-47013

Vulnerability from fkie_nvd - Published: 2024-02-28 09:15 - Updated: 2026-08-04 10:16

Severity

9.8 (Critical) - CVSS:3.1/AV:N/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

Summary

In the Linux kernel, the following vulnerability has been resolved: net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..). If some error happens in emac_tx_fill_tpd(), the skb will be freed via dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd(). But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len). As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len, thus my patch assigns skb->len to 'len' before the possible free and use 'len' instead of skb->len later.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/16d8c44be52e3650917736d45f5904384a9da834	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/55fcdd1258faaecca74b91b88cc0921f9edd775d	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6d72e7c767acbbdd44ebc7d89c6690b405b32b57	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8c06f34785068b87e2b560534c77c163d6c6dca7	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9dc373f74097edd0e35f3393d6248eda8d1ba99d	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c7f75d11fe72913d2619f97b2334b083cd7bb955	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/dc1b438a35773d030be0ee80d9c635c3e558a322	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e407495ba6788a67d1bd41714158c079e340879b	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/16d8c44be52e3650917736d45f5904384a9da834	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/55fcdd1258faaecca74b91b88cc0921f9edd775d	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/6d72e7c767acbbdd44ebc7d89c6690b405b32b57	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/8c06f34785068b87e2b560534c77c163d6c6dca7	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/9dc373f74097edd0e35f3393d6248eda8d1ba99d	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/c7f75d11fe72913d2619f97b2334b083cd7bb955	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/dc1b438a35773d030be0ee80d9c635c3e558a322	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/e407495ba6788a67d1bd41714158c079e340879b	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/qualcomm/emac/emac-mac.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
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              "versionType": "git"
            },
            {
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              "versionType": "git"
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            {
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              "versionType": "git"
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            {
              "lessThan": "9dc373f74097edd0e35f3393d6248eda8d1ba99d",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "8c06f34785068b87e2b560534c77c163d6c6dca7",
              "status": "affected",
              "version": "b9b17debc69d27cd55e21ee51a5ba7fc50a426cf",
              "versionType": "git"
            },
            {
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              "version": "b9b17debc69d27cd55e21ee51a5ba7fc50a426cf",
              "versionType": "git"
            },
            {
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          ]
        },
        {
          "defaultStatus": "affected",
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          "programFiles": [
            "drivers/net/ethernet/qualcomm/emac/emac-mac.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.9"
            },
            {
              "lessThan": "4.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.9.*",
              "status": "unaffected",
              "version": "4.9.269",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.14.*",
              "status": "unaffected",
              "version": "4.14.233",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.19.*",
              "status": "unaffected",
              "version": "4.19.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.119",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.37",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.11.*",
              "status": "unaffected",
              "version": "5.11.21",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.12.*",
              "status": "unaffected",
              "version": "5.12.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5330E43C-47EE-40CA-B1A9-C1AAC143732E",
              "versionEndExcluding": "4.9.269",
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            },
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            {
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            {
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            },
            {
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              "versionStartIncluding": "5.12",
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            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send\n\nIn emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..).\nIf some error happens in emac_tx_fill_tpd(), the skb will be freed via\ndev_kfree_skb(skb) in error branch of emac_tx_fill_tpd().\nBut the freed skb is still used via skb-\u003elen by netdev_sent_queue(,skb-\u003elen).\n\nAs i observed that emac_tx_fill_tpd() haven\u0027t modified the value of skb-\u003elen,\nthus my patch assigns skb-\u003elen to \u0027len\u0027 before the possible free and\nuse \u0027len\u0027 instead of skb-\u003elen later."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: net:emac/emac-mac: Se corrige un uso after free en emac_mac_tx_buf_send En emac_mac_tx_buf_send, llama a emac_tx_fill_tpd(..,skb,..). Si ocurre alg\u00fan error en emac_tx_fill_tpd(), el skb se liberar\u00e1 mediante dev_kfree_skb(skb) en la rama de error de emac_tx_fill_tpd(). Pero el skb liberado todav\u00eda se usa a trav\u00e9s de skb-\u0026gt;len por netdev_sent_queue(,skb-\u0026gt;len). Como observ\u00e9 que emac_tx_fill_tpd() no ha modificado el valor de skb-\u0026gt;len, por lo tanto mi parche asigna skb-\u0026gt;len a \u0027len\u0027 antes del posible free y usa \u0027len\u0027 en lugar de skb-\u0026gt;len m\u00e1s tarde."
    }
  ],
  "id": "CVE-2021-47013",
  "lastModified": "2026-08-04T10:16:41.567",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
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    "ssvcV203": [
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        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-47013",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-02-28T19:56:27.719807Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-02-28T09:15:38.800",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "url": "https://git.kernel.org/stable/c/16d8c44be52e3650917736d45f5904384a9da834"
    },
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      "source": "af854a3a-2127-422b-91ae-364da2661108",
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      "tags": [
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-47013 (GCVE-0-2021-47013)

Vulnerability from cvelistv5 – Published: 2024-02-28 08:13 – Updated: 2026-08-05 08:45

Title

net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send

Summary

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-02-28 19:56 UTC

Assigner

Linux CNA under the mitre root

CNA scorecard D 54/100 over 6618 records in the last 180 days details

References

8 references

URL	Tags
https://git.kernel.org/stable/c/c7f75d11fe72913d2…
https://git.kernel.org/stable/c/dc1b438a35773d030…
https://git.kernel.org/stable/c/16d8c44be52e36509…
https://git.kernel.org/stable/c/55fcdd1258faaecca…
https://git.kernel.org/stable/c/9dc373f74097edd0e…
https://git.kernel.org/stable/c/8c06f34785068b87e…
https://git.kernel.org/stable/c/e407495ba6788a67d…
https://git.kernel.org/stable/c/6d72e7c767acbbdd4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < c7f75d11fe72913d2619f97b2334b083cd7bb955 (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < dc1b438a35773d030be0ee80d9c635c3e558a322 (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < 16d8c44be52e3650917736d45f5904384a9da834 (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < 55fcdd1258faaecca74b91b88cc0921f9edd775d (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < 9dc373f74097edd0e35f3393d6248eda8d1ba99d (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < 8c06f34785068b87e2b560534c77c163d6c6dca7 (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < e407495ba6788a67d1bd41714158c079e340879b (git) Affected: b9b17debc69d27cd55e21ee51a5ba7fc50a426cf , < 6d72e7c767acbbdd44ebc7d89c6690b405b32b57 (git)
Linux	Linux	Affected: 4.9 Unaffected: 0 , < 4.9 (semver) Unaffected: 4.9.269 , ≤ 4.9.* (semver) Unaffected: 4.14.233 , ≤ 4.14.* (semver) Unaffected: 4.19.191 , ≤ 4.19.* (semver) Unaffected: 5.4.119 , ≤ 5.4.* (semver) Unaffected: 5.10.37 , ≤ 5.10.* (semver) Unaffected: 5.11.21 , ≤ 5.11.* (semver) Unaffected: 5.12.4 , ≤ 5.12.* (semver) Unaffected: 5.13 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47013",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
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                "role": "CISA Coordinator",
                "timestamp": "2024-02-28T19:56:27.719807Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:24:39.713Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
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        "references": [
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            "url": "https://git.kernel.org/stable/c/dc1b438a35773d030be0ee80d9c635c3e558a322"
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          "vendor": "Linux",
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              "version": "0",
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              "versionType": "semver"
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            {
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              "status": "unaffected",
              "version": "5.4.119",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "5.10.37",
              "versionType": "semver"
            },
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              "version": "5.11.21",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "5.12.4",
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            },
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              "status": "unaffected",
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              "versionType": "original_commit_for_fix"
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              "value": "AV:N - The bug is in the Qualcomm EMAC ndo_start_xmit path (emac_start_xmit \u2192 emac_mac_tx_buf_send), used on network-facing FSM9900/QDF platforms; a remote peer can drive TX via ARP/ICMP/TCP replies or forwarded traffic through this NIC, matching other ethernet TX CVEs.\nAC:L - An attacker can flood traffic to raise DMA/swiotlb pressure until dma_mapping_error() hits; once that failure occurs the UAF of skb-\u003elen is deterministic, as scored for similar dma_mapping_error TX bugs (e.g. CVE-2024-50170).\nPR:N - No authentication or capability check sits on this path\u2014unauthenticated remote traffic that elicits kernel TX, or an unprivileged local socket send, reaches emac_mac_tx_buf_send.\nUI:N - No victim action is required; ordinary network traffic or local sends autonomously exercise the transmit path.\nS:U - The UAF corrupts/abuses kernel skb and BQL state within the same host security authority; the TX ring produce index is rolled back on the error path so no IOMMU/DMA boundary is crossed.\nC:H - This is a use-after-free of an sk_buff: after dev_kfree_skb() the freed object can be reclaimed via heap spray, and UAF of skb metadata is treated as enabling arbitrary kernel memory disclosure primitives.\nI:H - Use-after-free of the skb enables heap reuse/type confusion and attacker-controlled BQL byte accounting via the post-free skb-\u003elen read, which is leverageable for memory corruption and control-flow impact.\nA:H - Dereferencing the freed skb can oops if the object is poisoned or unmapped, and the post-free netdev_sent_queue() permanently inflates BQL without a matching completion, enabling TX queue stall or kernel crash."
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    "cveId": "CVE-2021-47013",
    "datePublished": "2024-02-28T08:13:30.905Z",
    "dateReserved": "2024-02-27T18:42:55.953Z",
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}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

FKIE_CVE-2021-47013

CVE-2021-47013 (GCVE-0-2021-47013)

Tags

Sightings

Nomenclature

Related by attack behaviour