ubuntu-cve-2021-3828
Vulnerability from osv_ubuntu
Published
2021-09-27 13:15
Modified
2025-07-16 04:56
Summary
Details

nltk is vulnerable to Inefficient Regular Expression Complexity

Severity
7.5 (High)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "python-nltk",
            "binary_version": "3.1-1ubuntu0.1+esm1"
          },
          {
            "binary_name": "python3-nltk",
            "binary_version": "3.1-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "nltk",
        "purl": "pkg:deb/ubuntu/nltk@3.1-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.4-1",
        "3.0.5-1",
        "3.1-1",
        "3.1-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "python-nltk",
            "binary_version": "3.2.5-1ubuntu0.1+esm1"
          },
          {
            "binary_name": "python3-nltk",
            "binary_version": "3.2.5-1ubuntu0.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "nltk",
        "purl": "pkg:deb/ubuntu/nltk@3.2.5-1ubuntu0.1+esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2.5-1ubuntu0.1+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.2.4-1",
        "3.2.5-1",
        "3.2.5-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "python3-nltk",
            "binary_version": "3.4.5-2ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "nltk",
        "purl": "pkg:deb/ubuntu/nltk@3.4.5-2ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.5-2ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.4.5-1",
        "3.4.5-2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-nltk",
            "binary_version": "3.6.5-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "nltk",
        "purl": "pkg:deb/ubuntu/nltk@3.6.5-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6.5-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.5-1"
      ]
    }
  ],
  "aliases": [],
  "details": "nltk is vulnerable to Inefficient Regular Expression Complexity",
  "id": "UBUNTU-CVE-2021-3828",
  "modified": "2025-07-16T04:56:47Z",
  "published": "2021-09-27T13:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3828"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/nltk/nltk/pull/2816"
    },
    {
      "type": "REPORT",
      "url": "https://huntr.dev/bounties/d19aed43-75bc-4a03-91a0-4d0bb516bc32"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5215-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-3828"
    }
  ],
  "related": [
    "USN-5215-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-3828"
  ]
}



Log in or create an account to share your comment.




Tags
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.