Vulnerability-Lookup

FKIE_CVE-2021-23424

Vulnerability from fkie_nvd - Published: 2021-08-18 17:15 - Updated: 2026-06-17 03:38

Severity

7.5 (High) - CVSS:3.1/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

Summary

This affects all versions of package ansi-html. If an attacker provides a malicious string, it will get stuck processing the input for an extremely long time.

References

URL	Tags
report@snyk.io	https://github.com/Tjatse/ansi-html/issues/19	Exploit, Issue Tracking, Third Party Advisory
report@snyk.io	https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198	Exploit, Third Party Advisory
report@snyk.io	https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849	Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/Tjatse/ansi-html/issues/19	Exploit, Issue Tracking, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198	Exploit, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849	Exploit, Third Party Advisory

Impacted products

	Vendor	Product	Version
	ansi-html_project	ansi-html	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "ansi-html",
          "vendor": "n/a",
          "versions": [
            {
              "lessThan": "unspecified",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "report@snyk.io"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:ansi-html_project:ansi-html:*:*:*:*:*:node.js:*:*",
              "matchCriteriaId": "41E6CEEC-8D5E-4028-96CE-E5F937CB844A",
              "versionEndExcluding": "0.0.8",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "This affects all versions of package ansi-html. If an attacker provides a malicious string, it will get stuck processing the input for an extremely long time."
    },
    {
      "lang": "es",
      "value": "Esto afecta a todas las versiones del paquete ansi-html. Si un atacante proporciona una cadena maliciosa, se bloquear\u00e1 el procesamiento de la entrada durante un tiempo extremadamente largo."
    }
  ],
  "id": "CVE-2021-23424",
  "lastModified": "2026-06-17T03:38:44.290",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 5.0,
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "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"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "report@snyk.io",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "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"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-08-18T17:15:07.990",
  "references": [
    {
      "source": "report@snyk.io",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "url": "https://github.com/Tjatse/ansi-html/issues/19"
    },
    {
      "source": "report@snyk.io",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198"
    },
    {
      "source": "report@snyk.io",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Third Party Advisory"
      ],
      "url": "https://github.com/Tjatse/ansi-html/issues/19"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849"
    }
  ],
  "sourceIdentifier": "report@snyk.io",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-23424 (GCVE-0-2021-23424)

Vulnerability from cvelistv5 – Published: 2021-08-18 16:15 – Updated: 2024-09-16 17:38

Title

Regular Expression Denial of Service (ReDoS)

Summary

This affects all versions of package ansi-html. If an attacker provides a malicious string, it will get stuck processing the input for an extremely long time.

Severity

7.5 (High)


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

CWE

Regular Expression Denial of Service (ReDoS)

Assigner

snyk mitre root

References

3 references

URL	Tags
https://github.com/Tjatse/ansi-html/issues/19	x_refsource_MISC
https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849	x_refsource_MISC
https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
n/a	ansi-html	Affected: 0 , < unspecified (custom)

Date Public

2021-08-18 00:00

Credits

Ben Caller Robert McLaughlin

Show details on NVD website

JSON

To clipboard

{
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    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T19:05:55.989Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/Tjatse/ansi-html/issues/19"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "ansi-html",
          "vendor": "n/a",
          "versions": [
            {
              "lessThan": "unspecified",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Ben Caller"
        },
        {
          "lang": "en",
          "value": "Robert McLaughlin"
        }
      ],
      "datePublic": "2021-08-18T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "This affects all versions of package ansi-html. If an attacker provides a malicious string, it will get stuck processing the input for an extremely long time."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "exploitCodeMaturity": "PROOF_OF_CONCEPT",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "remediationLevel": "NOT_DEFINED",
            "reportConfidence": "NOT_DEFINED",
            "scope": "UNCHANGED",
            "temporalScore": 7.1,
            "temporalSeverity": "HIGH",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Regular Expression Denial of Service (ReDoS)",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
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      "references": [
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          "url": "https://github.com/Tjatse/ansi-html/issues/19"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1567198"
        }
      ],
      "title": "Regular Expression Denial of Service (ReDoS)",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "report@snyk.io",
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          "ID": "CVE-2021-23424",
          "STATE": "PUBLIC",
          "TITLE": "Regular Expression Denial of Service (ReDoS)"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "ansi-html",
                      "version": {
                        "version_data": [
                          {
                            "version_affected": "\u003e=",
                            "version_value": "0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "credit": [
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            "lang": "eng",
            "value": "Ben Caller"
          },
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            "value": "Robert McLaughlin"
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            "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/E:P",
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              "name": "https://github.com/Tjatse/ansi-html/issues/19",
              "refsource": "MISC",
              "url": "https://github.com/Tjatse/ansi-html/issues/19"
            },
            {
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              "refsource": "MISC",
              "url": "https://snyk.io/vuln/SNYK-JS-ANSIHTML-1296849"
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    "datePublished": "2021-08-18T16:15:17.036Z",
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    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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}

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.