Vulnerability-Lookup

CNVD-2021-52408

Vulnerability from cnvd - Published: 2021-07-20

Title

SELinux缓冲区溢出漏洞

Description

SELinux是美国国家安全局（National Security Agency）的一种采用安全架构的Linux子系统，它能够让管理员更好地管控哪些人可以访问系统。 SELinux 3.2版本存在安全漏洞，该漏洞源于SELinux 3.2中的CIL编译器在\"ebitmap match any\"中有一个基于堆的缓冲区溢出。目前没有详细的漏洞细节提供。

Severity

低

Patch Name

SELinux缓冲区溢出漏洞的补丁

Patch Description

Formal description

目前厂商已发布升级补丁以修复漏洞，补丁获取链接： https://oss-fuzz.com/revisions?job=libfuzzer_asan_selinux&range=202104191800:202104200000。

Reference

https://nvd.nist.gov/vuln/detail/CVE-2021-36087

Impacted products

Name
National Security Agency SELinux 3.2

Show details on source website

JSON

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{
  "cves": {
    "cve": {
      "cveNumber": "CVE-2021-36087"
    }
  },
  "description": "SELinux\u662f\u7f8e\u56fd\u56fd\u5bb6\u5b89\u5168\u5c40\uff08National Security Agency\uff09\u7684\u4e00\u79cd\u91c7\u7528\u5b89\u5168\u67b6\u6784\u7684Linux\u5b50\u7cfb\u7edf\uff0c\u5b83\u80fd\u591f\u8ba9\u7ba1\u7406\u5458\u66f4\u597d\u5730\u7ba1\u63a7\u54ea\u4e9b\u4eba\u53ef\u4ee5\u8bbf\u95ee\u7cfb\u7edf\u3002\n\nSELinux 3.2\u7248\u672c\u5b58\u5728\u5b89\u5168\u6f0f\u6d1e\uff0c\u8be5\u6f0f\u6d1e\u6e90\u4e8eSELinux 3.2\u4e2d\u7684CIL\u7f16\u8bd1\u5668\u5728\\\"ebitmap match any\\\"\u4e2d\u6709\u4e00\u4e2a\u57fa\u4e8e\u5806\u7684\u7f13\u51b2\u533a\u6ea2\u51fa\u3002\u76ee\u524d\u6ca1\u6709\u8be6\u7ec6\u7684\u6f0f\u6d1e\u7ec6\u8282\u63d0\u4f9b\u3002",
  "formalWay": "\u76ee\u524d\u5382\u5546\u5df2\u53d1\u5e03\u5347\u7ea7\u8865\u4e01\u4ee5\u4fee\u590d\u6f0f\u6d1e\uff0c\u8865\u4e01\u83b7\u53d6\u94fe\u63a5\uff1a\r\nhttps://oss-fuzz.com/revisions?job=libfuzzer_asan_selinux\u0026range=202104191800:202104200000\u3002",
  "isEvent": "\u901a\u7528\u8f6f\u786c\u4ef6\u6f0f\u6d1e",
  "number": "CNVD-2021-52408",
  "openTime": "2021-07-20",
  "patchDescription": "SELinux\u662f\u7f8e\u56fd\u56fd\u5bb6\u5b89\u5168\u5c40\uff08National Security Agency\uff09\u7684\u4e00\u79cd\u91c7\u7528\u5b89\u5168\u67b6\u6784\u7684Linux\u5b50\u7cfb\u7edf\uff0c\u5b83\u80fd\u591f\u8ba9\u7ba1\u7406\u5458\u66f4\u597d\u5730\u7ba1\u63a7\u54ea\u4e9b\u4eba\u53ef\u4ee5\u8bbf\u95ee\u7cfb\u7edf\u3002\r\n\r\nSELinux 3.2\u7248\u672c\u5b58\u5728\u5b89\u5168\u6f0f\u6d1e\uff0c\u8be5\u6f0f\u6d1e\u6e90\u4e8eSELinux 3.2\u4e2d\u7684CIL\u7f16\u8bd1\u5668\u5728\\\"ebitmap match any\\\"\u4e2d\u6709\u4e00\u4e2a\u57fa\u4e8e\u5806\u7684\u7f13\u51b2\u533a\u6ea2\u51fa\u3002\u76ee\u524d\u6ca1\u6709\u8be6\u7ec6\u7684\u6f0f\u6d1e\u7ec6\u8282\u63d0\u4f9b\u3002\u76ee\u524d\uff0c\u4f9b\u5e94\u5546\u53d1\u5e03\u4e86\u5b89\u5168\u516c\u544a\u53ca\u76f8\u5173\u8865\u4e01\u4fe1\u606f\uff0c\u4fee\u590d\u4e86\u6b64\u6f0f\u6d1e\u3002",
  "patchName": "SELinux\u7f13\u51b2\u533a\u6ea2\u51fa\u6f0f\u6d1e\u7684\u8865\u4e01",
  "products": {
    "product": "National Security Agency SELinux 3.2"
  },
  "referenceLink": "https://nvd.nist.gov/vuln/detail/CVE-2021-36087",
  "serverity": "\u4f4e",
  "submitTime": "2021-07-02",
  "title": "SELinux\u7f13\u51b2\u533a\u6ea2\u51fa\u6f0f\u6d1e"
}

CVE-2021-36087 (GCVE-0-2021-36087)

Vulnerability from cvelistv5 – Published: 2021-07-01 02:49 – Updated: 2025-11-03 21:44

Summary

The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in ebitmap_match_any (called indirectly from cil_check_neverallow). This occurs because there is sometimes a lack of checks for invalid statements in an optional block.

Severity

No CVSS data available.

CWE

Assigner

mitre mitre root

References

7 references

URL	Tags
https://github.com/google/oss-fuzz-vulns/blob/mai…	x_refsource_MISC
https://bugs.chromium.org/p/oss-fuzz/issues/detai…	x_refsource_MISC
https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnx…	x_refsource_MISC
https://github.com/SELinuxProject/selinux/commit/…	x_refsource_MISC
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA
https://security.netapp.com/advisory/ntap-2025020…
https://lists.debian.org/debian-lts-announce/2024…

Show details on NVD website

JSON

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{
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    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T21:44:57.912Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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        "references": [
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            ],
            "url": "https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-585.yaml"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ%40mail.gmail.com/T/"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521"
          },
          {
            "name": "FEDORA-2021-67efe88c29",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/"
          },
          {
            "url": "https://security.netapp.com/advisory/ntap-20250207-0004/"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2024/10/msg00021.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
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          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in ebitmap_match_any (called indirectly from cil_check_neverallow). This occurs because there is sometimes a lack of checks for invalid statements in an optional block."
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      "providerMetadata": {
        "dateUpdated": "2021-11-15T07:06:34.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-585.yaml"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ%40mail.gmail.com/T/"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521"
        },
        {
          "name": "FEDORA-2021-67efe88c29",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
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          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-36087",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
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                      }
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                },
                "vendor_name": "n/a"
              }
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        "description": {
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          ]
        },
        "problemtype": {
          "problemtype_data": [
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              "url": "https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-585.yaml"
            },
            {
              "name": "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675",
              "refsource": "MISC",
              "url": "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675"
            },
            {
              "name": "https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ@mail.gmail.com/T/",
              "refsource": "MISC",
              "url": "https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ@mail.gmail.com/T/"
            },
            {
              "name": "https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521",
              "refsource": "MISC",
              "url": "https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521"
            },
            {
              "name": "FEDORA-2021-67efe88c29",
              "refsource": "FEDORA",
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    "assignerShortName": "mitre",
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    "datePublished": "2021-07-01T02:49:55.000Z",
    "dateReserved": "2021-07-01T00:00:00.000Z",
    "dateUpdated": "2025-11-03T21:44:57.912Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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.