CVE-2021-32837 (GCVE-0-2021-32837)

Vulnerability from cvelistv5 – Published: 2023-01-17 00:00 – Updated: 2025-12-22 01:32
VLAI?
Title
mechanize vulnerable to ReDoS
Summary
mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue.
Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
Impacted products
Vendor Product Version
python-mechanize mechanize Affected: 0.4.6 , < 0.4.6 (custom)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-12-22T01:32:19.985Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6"
          },
          {
            "name": "[debian-lts-announce] 20230620 [SECURITY] [DLA 3460-1] python-mechanize security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/12/msg00028.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-32837",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-03-10T21:02:11.874134Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-03-10T21:22:55.702Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "mechanize",
          "vendor": "python-mechanize",
          "versions": [
            {
              "lessThan": "0.4.6",
              "status": "affected",
              "version": "0.4.6",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1333",
              "description": "CWE-1333 Inefficient Regular Expression Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-06-20T00:00:00.000Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "url": "https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/"
        },
        {
          "url": "https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879"
        },
        {
          "url": "https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6"
        },
        {
          "url": "https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6"
        },
        {
          "name": "[debian-lts-announce] 20230620 [SECURITY] [DLA 3460-1] python-mechanize security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html"
        }
      ],
      "source": {
        "advisory": "GHSL-2021-108",
        "defect": [
          "GHSL-2021-108"
        ],
        "discovery": "UNKNOWN"
      },
      "title": "mechanize vulnerable to ReDoS",
      "x_generator": {
        "engine": "Vulnogram 0.0.9"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-32837",
    "datePublished": "2023-01-17T00:00:00.000Z",
    "dateReserved": "2021-05-12T00:00:00.000Z",
    "dateUpdated": "2025-12-22T01:32:19.985Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "fkie_nvd": {
      "configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:mechanize_project:mechanize:*:*:*:*:*:python:*:*\", \"versionEndExcluding\": \"0.4.6\", \"matchCriteriaId\": \"29D79742-1F31-48EC-B67A-A49B3B73EADE\"}]}]}]",
      "descriptions": "[{\"lang\": \"en\", \"value\": \"mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue.\"}, {\"lang\": \"es\", \"value\": \"mechanize, una librer\\u00eda para interactuar autom\\u00e1ticamente con servidores web HTTP, contiene una expresi\\u00f3n regular que es vulnerable a la denegaci\\u00f3n de servicio de expresi\\u00f3n regular (ReDoS) antes de la versi\\u00f3n 0.4.6. Si un servidor web responde de forma maliciosa, mechanize podr\\u00eda fallar. La versi\\u00f3n 0.4.6 tiene un parche para este problema.\"}]",
      "id": "CVE-2021-32837",
      "lastModified": "2024-11-21T06:07:51.193",
      "metrics": "{\"cvssMetricV31\": [{\"source\": \"security-advisories@github.com\", \"type\": \"Secondary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"baseScore\": 7.5, \"baseSeverity\": \"HIGH\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"HIGH\"}, \"exploitabilityScore\": 3.9, \"impactScore\": 3.6}, {\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"baseScore\": 7.5, \"baseSeverity\": \"HIGH\", \"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"NONE\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"HIGH\"}, \"exploitabilityScore\": 3.9, \"impactScore\": 3.6}]}",
      "published": "2023-01-17T22:15:10.533",
      "references": "[{\"url\": \"https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879\", \"source\": \"security-advisories@github.com\", \"tags\": [\"Exploit\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6\", \"source\": \"security-advisories@github.com\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6\", \"source\": \"security-advisories@github.com\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html\", \"source\": \"security-advisories@github.com\"}, {\"url\": \"https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/\", \"source\": \"security-advisories@github.com\", \"tags\": [\"Exploit\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Exploit\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Exploit\", \"Third Party Advisory\"]}]",
      "sourceIdentifier": "security-advisories@github.com",
      "vulnStatus": "Modified",
      "weaknesses": "[{\"source\": \"security-advisories@github.com\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-1333\"}]}]"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-32837\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2023-01-17T22:15:10.533\",\"lastModified\":\"2025-12-22T02:16:01.123\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue.\"},{\"lang\":\"es\",\"value\":\"mechanize, una librer\u00eda para interactuar autom\u00e1ticamente con servidores web HTTP, contiene una expresi\u00f3n regular que es vulnerable a la denegaci\u00f3n de servicio de expresi\u00f3n regular (ReDoS) antes de la versi\u00f3n 0.4.6. Si un servidor web responde de forma maliciosa, mechanize podr\u00eda fallar. La versi\u00f3n 0.4.6 tiene un parche para este problema.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-1333\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:mechanize_project:mechanize:*:*:*:*:*:python:*:*\",\"versionEndExcluding\":\"0.4.6\",\"matchCriteriaId\":\"29D79742-1F31-48EC-B67A-A49B3B73EADE\"}]}]}],\"references\":[{\"url\":\"https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.debian.org/debian-lts-announce/2025/12/msg00028.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html\", \"name\": \"[debian-lts-announce] 20230620 [SECURITY] [DLA 3460-1] python-mechanize security update\", \"tags\": [\"mailing-list\", \"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2025/12/msg00028.html\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2025-12-22T01:32:19.985Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-32837\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-03-10T21:02:11.874134Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-03-10T21:02:13.189Z\"}}], \"cna\": {\"title\": \"mechanize vulnerable to ReDoS\", \"source\": {\"defect\": [\"GHSL-2021-108\"], \"advisory\": \"GHSL-2021-108\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"python-mechanize\", \"product\": \"mechanize\", \"versions\": [{\"status\": \"affected\", \"version\": \"0.4.6\", \"lessThan\": \"0.4.6\", \"versionType\": \"custom\"}]}], \"references\": [{\"url\": \"https://securitylab.github.com/advisories/GHSL-2021-108-python-mechanize-mechanize/\"}, {\"url\": \"https://github.com/python-mechanize/mechanize/blob/3acb1836f3fd8edc5a758a417dd46b53832ae3b5/mechanize/_urllib2_fork.py#L878-L879\"}, {\"url\": \"https://github.com/python-mechanize/mechanize/releases/tag/v0.4.6\"}, {\"url\": \"https://github.com/python-mechanize/mechanize/commit/dd05334448e9f39814bab044d2eaa5ef69b410d6\"}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/06/msg00022.html\", \"name\": \"[debian-lts-announce] 20230620 [SECURITY] [DLA 3460-1] python-mechanize security update\", \"tags\": [\"mailing-list\"]}], \"x_generator\": {\"engine\": \"Vulnogram 0.0.9\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-1333\", \"description\": \"CWE-1333 Inefficient Regular Expression Complexity\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2023-06-20T00:00:00.000Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-32837\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-12-22T01:32:19.985Z\", \"dateReserved\": \"2021-05-12T00:00:00.000Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2023-01-17T00:00:00.000Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.