Vulnerability-Lookup

CNVD-2021-22851

Vulnerability from cnvd - Published: 2021-03-26

Title

Pygments拒绝服务攻击漏洞

Description

Pygments是一种通用语法高亮显示工具，适用于代码托管、论坛、维基或其他需要美化源代码的应用程序。 Pygments 1.5到2.7.3版本存在拒绝服务漏洞。漏洞产生的原因是Pygments中的SMLLexer中的无限循环。攻击者可以利用此漏洞导致在执行标准ML（SML）源文件的语法突出显示时拒绝服务。

Severity

中

Formal description

厂商未提供漏洞修复方案，请关注厂商主页更新： https://pygments.org/docs/

Reference

https://nvd.nist.gov/vuln/detail/CVE-2021-20270

Impacted products

Name
Pygments Pygments >=1.5，<=2.7.3

Show details on source website

JSON

To clipboard

{
  "cves": {
    "cve": {
      "cveNumber": "CVE-2021-20270",
      "cveUrl": "https://nvd.nist.gov/vuln/detail/CVE-2021-20270"
    }
  },
  "description": "Pygments\u662f\u4e00\u79cd\u901a\u7528\u8bed\u6cd5\u9ad8\u4eae\u663e\u793a\u5de5\u5177\uff0c\u9002\u7528\u4e8e\u4ee3\u7801\u6258\u7ba1\u3001\u8bba\u575b\u3001\u7ef4\u57fa\u6216\u5176\u4ed6\u9700\u8981\u7f8e\u5316\u6e90\u4ee3\u7801\u7684\u5e94\u7528\u7a0b\u5e8f\u3002\n\nPygments 1.5\u52302.7.3\u7248\u672c\u5b58\u5728\u62d2\u7edd\u670d\u52a1\u6f0f\u6d1e\u3002\u6f0f\u6d1e\u4ea7\u751f\u7684\u539f\u56e0\u662fPygments\u4e2d\u7684SMLLexer\u4e2d\u7684\u65e0\u9650\u5faa\u73af\u3002\u653b\u51fb\u8005\u53ef\u4ee5\u5229\u7528\u6b64\u6f0f\u6d1e\u5bfc\u81f4\u5728\u6267\u884c\u6807\u51c6ML\uff08SML\uff09\u6e90\u6587\u4ef6\u7684\u8bed\u6cd5\u7a81\u51fa\u663e\u793a\u65f6\u62d2\u7edd\u670d\u52a1\u3002",
  "formalWay": "\u5382\u5546\u672a\u63d0\u4f9b\u6f0f\u6d1e\u4fee\u590d\u65b9\u6848\uff0c\u8bf7\u5173\u6ce8\u5382\u5546\u4e3b\u9875\u66f4\u65b0\uff1a\r\nhttps://pygments.org/docs/",
  "isEvent": "\u901a\u7528\u8f6f\u786c\u4ef6\u6f0f\u6d1e",
  "number": "CNVD-2021-22851",
  "openTime": "2021-03-26",
  "products": {
    "product": "Pygments Pygments \u003e=1.5\uff0c\u003c=2.7.3"
  },
  "referenceLink": "https://nvd.nist.gov/vuln/detail/CVE-2021-20270",
  "serverity": "\u4e2d",
  "submitTime": "2021-03-25",
  "title": "Pygments\u62d2\u7edd\u670d\u52a1\u653b\u51fb\u6f0f\u6d1e"
}

CVE-2021-20270 (GCVE-0-2021-20270)

Vulnerability from cvelistv5 – Published: 2021-03-23 16:40 – Updated: 2024-08-03 17:37

Summary

An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Severity

No CVSS data available.

CWE

CWE-835

Assigner

redhat redhat root

References

5 references

URL	Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1922136	x_refsource_MISC
https://www.debian.org/security/2021/dsa-4889	vendor-advisoryx_refsource_DEBIAN
https://lists.debian.org/debian-lts-announce/2021…	mailing-listx_refsource_MLIST
https://lists.debian.org/debian-lts-announce/2021…	mailing-listx_refsource_MLIST
https://www.oracle.com/security-alerts/cpuoct2021.html	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
n/a	python-pygments	Affected: python-pygments 2.7.4

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T17:37:23.034Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1922136"
          },
          {
            "name": "DSA-4889",
            "tags": [
              "vendor-advisory",
              "x_refsource_DEBIAN",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2021/dsa-4889"
          },
          {
            "name": "[debian-lts-announce] 20210505 [SECURITY] [DLA 2648-1] mediawiki security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html"
          },
          {
            "name": "[debian-lts-announce] 20210506 [SECURITY] [DLA 2648-2] mediawiki regression update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "python-pygments",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "python-pygments 2.7.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the \"exception\" keyword."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-835",
              "description": "CWE-835",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-10-20T10:40:34.000Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1922136"
        },
        {
          "name": "DSA-4889",
          "tags": [
            "vendor-advisory",
            "x_refsource_DEBIAN"
          ],
          "url": "https://www.debian.org/security/2021/dsa-4889"
        },
        {
          "name": "[debian-lts-announce] 20210505 [SECURITY] [DLA 2648-1] mediawiki security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html"
        },
        {
          "name": "[debian-lts-announce] 20210506 [SECURITY] [DLA 2648-2] mediawiki regression update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "secalert@redhat.com",
          "ID": "CVE-2021-20270",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "python-pygments",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "python-pygments 2.7.4"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the \"exception\" keyword."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-835"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://bugzilla.redhat.com/show_bug.cgi?id=1922136",
              "refsource": "MISC",
              "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1922136"
            },
            {
              "name": "DSA-4889",
              "refsource": "DEBIAN",
              "url": "https://www.debian.org/security/2021/dsa-4889"
            },
            {
              "name": "[debian-lts-announce] 20210505 [SECURITY] [DLA 2648-1] mediawiki security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html"
            },
            {
              "name": "[debian-lts-announce] 20210506 [SECURITY] [DLA 2648-2] mediawiki regression update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html"
            },
            {
              "name": "https://www.oracle.com/security-alerts/cpuoct2021.html",
              "refsource": "MISC",
              "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2021-20270",
    "datePublished": "2021-03-23T16:40:22.000Z",
    "dateReserved": "2020-12-17T00:00:00.000Z",
    "dateUpdated": "2024-08-03T17:37:23.034Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

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.

Action not permitted

CNVD-2021-22851

CVE-2021-20270 (GCVE-0-2021-20270)

Tags

Sightings

Nomenclature

Related by attack behaviour