CVE-2021-3426 (GCVE-0-2021-3426)
Vulnerability from cvelistv5
Published
2021-05-20 00:00
Modified
2025-12-18 11:45
CWE
Summary
There's a flaw in Python 3's pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.
Impacted products
Vendor Product Version
n/a python Version: python 3.8.9, python 3.9.3, python 3.10.0a7
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T21:44:51.975Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "[debian-lts-announce] 20210405 [SECURITY] [DLA 2619-1] python3.5 security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html"
          },
          {
            "name": "FEDORA-2021-a311bf10d4",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25HVHLBGO2KNPXJ3G426QEYSSCECJDU5/"
          },
          {
            "name": "FEDORA-2021-2ab6f060d9",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VPX7Y5GQDNB4FJTREWONGC4ZSVH7TGHF/"
          },
          {
            "name": "FEDORA-2021-1769a23935",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DQYPUKLLBOZMKFPO7RD7CENTXHUUEUV7/"
          },
          {
            "name": "FEDORA-2021-b6b6093b3a",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N6VXJZSZ6N64AILJX4CTMACYGQGHHD5C/"
          },
          {
            "name": "FEDORA-2021-067c9deff1",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QNGAFMPIYIVJ47FCF2NK2PIX22HUG35B/"
          },
          {
            "name": "FEDORA-2021-0a8f3ffbc0",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BF2K7HEWADHN6P52R3QLIOX27U3DJ4HI/"
          },
          {
            "name": "FEDORA-2021-a26257ccf5",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LM5V4VPLBHBEASSAROYPSHXGXGGPHNOE/"
          },
          {
            "name": "GLSA-202104-04",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/202104-04"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1935913"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210629-0003/"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpujan2022.html"
          },
          {
            "name": "[debian-lts-announce] 20230630 [SECURITY] [DLA 3477-1] python3.7 security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "ADJACENT_NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.7,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-3426",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-12-18T11:45:51.350788Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-12-18T11:45:56.551Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "python",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "python 3.8.9, python 3.9.3, python 3.10.0a7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "There\u0027s a flaw in Python 3\u0027s pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-200",
              "description": "CWE-200",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-06-30T00:00:00.000Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "name": "[debian-lts-announce] 20210405 [SECURITY] [DLA 2619-1] python3.5 security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html"
        },
        {
          "name": "FEDORA-2021-a311bf10d4",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25HVHLBGO2KNPXJ3G426QEYSSCECJDU5/"
        },
        {
          "name": "FEDORA-2021-2ab6f060d9",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VPX7Y5GQDNB4FJTREWONGC4ZSVH7TGHF/"
        },
        {
          "name": "FEDORA-2021-1769a23935",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DQYPUKLLBOZMKFPO7RD7CENTXHUUEUV7/"
        },
        {
          "name": "FEDORA-2021-b6b6093b3a",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N6VXJZSZ6N64AILJX4CTMACYGQGHHD5C/"
        },
        {
          "name": "FEDORA-2021-067c9deff1",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QNGAFMPIYIVJ47FCF2NK2PIX22HUG35B/"
        },
        {
          "name": "FEDORA-2021-0a8f3ffbc0",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BF2K7HEWADHN6P52R3QLIOX27U3DJ4HI/"
        },
        {
          "name": "FEDORA-2021-a26257ccf5",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LM5V4VPLBHBEASSAROYPSHXGXGGPHNOE/"
        },
        {
          "name": "GLSA-202104-04",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://security.gentoo.org/glsa/202104-04"
        },
        {
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1935913"
        },
        {
          "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
        },
        {
          "url": "https://security.netapp.com/advisory/ntap-20210629-0003/"
        },
        {
          "url": "https://www.oracle.com/security-alerts/cpujan2022.html"
        },
        {
          "name": "[debian-lts-announce] 20230630 [SECURITY] [DLA 3477-1] python3.7 security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2021-3426",
    "datePublished": "2021-05-20T00:00:00.000Z",
    "dateReserved": "2021-03-09T00:00:00.000Z",
    "dateUpdated": "2025-12-18T11:45:56.551Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html\", \"name\": \"[debian-lts-announce] 20210405 [SECURITY] [DLA 2619-1] python3.5 security update\", \"tags\": [\"mailing-list\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25HVHLBGO2KNPXJ3G426QEYSSCECJDU5/\", \"name\": \"FEDORA-2021-a311bf10d4\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VPX7Y5GQDNB4FJTREWONGC4ZSVH7TGHF/\", \"name\": \"FEDORA-2021-2ab6f060d9\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DQYPUKLLBOZMKFPO7RD7CENTXHUUEUV7/\", \"name\": \"FEDORA-2021-1769a23935\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N6VXJZSZ6N64AILJX4CTMACYGQGHHD5C/\", \"name\": \"FEDORA-2021-b6b6093b3a\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QNGAFMPIYIVJ47FCF2NK2PIX22HUG35B/\", \"name\": \"FEDORA-2021-067c9deff1\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BF2K7HEWADHN6P52R3QLIOX27U3DJ4HI/\", \"name\": \"FEDORA-2021-0a8f3ffbc0\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LM5V4VPLBHBEASSAROYPSHXGXGGPHNOE/\", \"name\": \"FEDORA-2021-a26257ccf5\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://security.gentoo.org/glsa/202104-04\", \"name\": \"GLSA-202104-04\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=1935913\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://www.oracle.com/security-alerts/cpuoct2021.html\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://security.netapp.com/advisory/ntap-20210629-0003/\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://www.oracle.com/security-alerts/cpujan2022.html\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html\", \"name\": \"[debian-lts-announce] 20230630 [SECURITY] [DLA 3477-1] python3.7 security update\", \"tags\": [\"mailing-list\", \"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2025-11-03T21:44:51.975Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.7, \"attackVector\": \"ADJACENT_NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-3426\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-12-18T11:45:51.350788Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-12-18T11:45:04.732Z\"}}], \"cna\": {\"affected\": [{\"vendor\": \"n/a\", \"product\": \"python\", \"versions\": [{\"status\": \"affected\", \"version\": \"python 3.8.9, python 3.9.3, python 3.10.0a7\"}]}], \"references\": [{\"url\": \"https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html\", \"name\": \"[debian-lts-announce] 20210405 [SECURITY] [DLA 2619-1] python3.5 security update\", \"tags\": [\"mailing-list\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25HVHLBGO2KNPXJ3G426QEYSSCECJDU5/\", \"name\": \"FEDORA-2021-a311bf10d4\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VPX7Y5GQDNB4FJTREWONGC4ZSVH7TGHF/\", \"name\": \"FEDORA-2021-2ab6f060d9\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DQYPUKLLBOZMKFPO7RD7CENTXHUUEUV7/\", \"name\": \"FEDORA-2021-1769a23935\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N6VXJZSZ6N64AILJX4CTMACYGQGHHD5C/\", \"name\": \"FEDORA-2021-b6b6093b3a\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QNGAFMPIYIVJ47FCF2NK2PIX22HUG35B/\", \"name\": \"FEDORA-2021-067c9deff1\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BF2K7HEWADHN6P52R3QLIOX27U3DJ4HI/\", \"name\": \"FEDORA-2021-0a8f3ffbc0\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LM5V4VPLBHBEASSAROYPSHXGXGGPHNOE/\", \"name\": \"FEDORA-2021-a26257ccf5\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://security.gentoo.org/glsa/202104-04\", \"name\": \"GLSA-202104-04\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=1935913\"}, {\"url\": \"https://www.oracle.com/security-alerts/cpuoct2021.html\"}, {\"url\": \"https://security.netapp.com/advisory/ntap-20210629-0003/\"}, {\"url\": \"https://www.oracle.com/security-alerts/cpujan2022.html\"}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html\", \"name\": \"[debian-lts-announce] 20230630 [SECURITY] [DLA 3477-1] python3.7 security update\", \"tags\": [\"mailing-list\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"There\u0027s a flaw in Python 3\u0027s pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-200\", \"description\": \"CWE-200\"}]}], \"providerMetadata\": {\"orgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"shortName\": \"redhat\", \"dateUpdated\": \"2023-06-30T00:00:00.000Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-3426\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-12-18T11:45:56.551Z\", \"dateReserved\": \"2021-03-09T00:00:00.000Z\", \"assignerOrgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"datePublished\": \"2021-05-20T00:00:00.000Z\", \"assignerShortName\": \"redhat\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…