Vulnerability-Lookup

ubuntu-cve-2021-34813

Vulnerability from osv_ubuntu

Published

2021-06-16 18:15

Modified

2026-04-22 07:40

Summary

Details

Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.

Severity

9.8 (Critical)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-34813	REPORT
	https://gitlab.matrix.org/matrix-org/olm/-/commit…	REPORT
	https://gitlab.matrix.org/matrix-org/olm/-/releas…	REPORT
	https://matrix.org/blog/2021/06/14/adventures-in-…	REPORT
	https://ubuntu.com/security/notices/USN-5194-1	ADVISORY
	https://www.cve.org/CVERecord?id=CVE-2021-34813	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libolm3",
            "binary_version": "3.1.3+dfsg-2ubuntu0.1~esm1"
          },
          {
            "binary_name": "python3-olm",
            "binary_version": "3.1.3+dfsg-2ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "olm",
        "purl": "pkg:deb/ubuntu/olm@3.1.3+dfsg-2ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.3+dfsg-2ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.1.3+dfsg-2",
        "3.1.3+dfsg-2build1",
        "3.1.3+dfsg-2build2"
      ]
    }
  ],
  "aliases": [],
  "details": "Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.",
  "id": "UBUNTU-CVE-2021-34813",
  "modified": "2026-04-22T07:40:05Z",
  "published": "2021-06-16T18:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-34813"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3"
    },
    {
      "type": "REPORT",
      "url": "https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5194-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-34813"
    }
  ],
  "related": [
    "USN-5194-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-34813"
  ]
}

CVE-2021-34813 (GCVE-0-2021-34813)

Vulnerability from cvelistv5 – Published: 2021-06-16 17:11 – Updated: 2024-08-04 00:26

Summary

Severity

No CVSS data available.

CWE

Assigner

mitre

References

3 references

URL	Tags
https://matrix.org/blog/2021/06/14/adventures-in-…	x_refsource_MISC
https://gitlab.matrix.org/matrix-org/olm/-/releas…	x_refsource_MISC
https://gitlab.matrix.org/matrix-org/olm/-/commit…	x_refsource_MISC

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T00:26:54.020Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-06-16T17:11:53.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-34813",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm",
              "refsource": "MISC",
              "url": "https://matrix.org/blog/2021/06/14/adventures-in-fuzzing-libolm"
            },
            {
              "name": "https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3",
              "refsource": "MISC",
              "url": "https://gitlab.matrix.org/matrix-org/olm/-/releases/3.2.3"
            },
            {
              "name": "https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b",
              "refsource": "MISC",
              "url": "https://gitlab.matrix.org/matrix-org/olm/-/commit/ccc0d122ee1b4d5e5ca4ec1432086be17d5f901b"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-34813",
    "datePublished": "2021-06-16T17:11:53.000Z",
    "dateReserved": "2021-06-16T00:00:00.000Z",
    "dateUpdated": "2024-08-04T00:26:54.020Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

usn-5194-1

Vulnerability from osv_ubuntu

Published

2021-12-15 13:45

Modified

2026-04-22 07:37

Summary

olm vulnerability

Details

Denis Kasak discovered that Olm was not verifying the length of input being processed by the olm_pk_decrypt module, which introduced a stack-based buffer overflow vulnerability to the library. An attacker could use this to cause a denial of service (application crash) or possibly execute arbitrary code.

References

URL

Type

	https://ubuntu.com/security/notices/USN-5194-1	ADVISORY
	https://ubuntu.com/security/CVE-2021-34813	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2021-34813",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:20.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libolm3",
            "binary_version": "3.1.3+dfsg-2ubuntu0.1~esm1"
          },
          {
            "binary_name": "python3-olm",
            "binary_version": "3.1.3+dfsg-2ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "olm",
        "purl": "pkg:deb/ubuntu/olm@3.1.3+dfsg-2ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.3+dfsg-2ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.1.3+dfsg-2",
        "3.1.3+dfsg-2build1",
        "3.1.3+dfsg-2build2"
      ]
    }
  ],
  "aliases": [],
  "details": "Denis Kasak discovered that Olm was not verifying the length of input being\nprocessed by the olm_pk_decrypt module, which introduced a stack-based buffer\noverflow vulnerability to the library. An attacker could use this to\ncause a denial of service (application crash) or possibly execute arbitrary code.\n",
  "id": "USN-5194-1",
  "modified": "2026-04-22T07:37:00Z",
  "published": "2021-12-15T13:45:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5194-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-34813"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "olm vulnerability",
  "upstream": [
    "UBUNTU-CVE-2021-34813"
  ]
}

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.

Action not permitted

ubuntu-cve-2021-34813

Vulnerability from osv_ubuntu

CVE-2021-34813 (GCVE-0-2021-34813)

usn-5194-1

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature