pysec - pysec-2021-13

PYSEC-2021-13

Vulnerability from pysec - Published: 2021-05-13 23:15 - Updated: 2023-07-25 00:34

Details

Impacted products

Name	purl
flask-caching	pkg:pypi/flask-caching

Aliases

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "flask-caching",
        "purl": "pkg:pypi/flask-caching"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0",
        "1.0.1",
        "1.1.0",
        "1.1.1",
        "1.2.0",
        "1.3.0",
        "1.3.1",
        "1.3.2",
        "1.3.3",
        "1.4.0",
        "1.5.0",
        "1.6.0",
        "1.7.0",
        "1.7.1",
        "1.7.2",
        "1.8.0",
        "1.9.0",
        "1.10.0",
        "1.10.1",
        "1.11.0",
        "1.11.1",
        "2.0.0",
        "2.0.1",
        "2.0.2"
      ]
    }
  ],
  "aliases": [
    "CVE-2021-33026",
    "GHSA-656c-6cxf-hvcv"
  ],
  "details": "The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code.",
  "id": "PYSEC-2021-13",
  "modified": "2023-07-25T00:34:15.721702Z",
  "published": "2021-05-13T23:15:00Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/sh4nks/flask-caching/pull/209"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-656c-6cxf-hvcv"
    }
  ],
  "withdrawn": "2023-07-25T12:32:00Z"
}

GHSA-656C-6CXF-HVCV

Vulnerability from github – Published: 2021-06-18 18:33 – Updated: 2022-09-20 13:31

Summary

Deserialization of Untrusted Data in Flask-Caching

Details

Flask-Cache adds easy cache support to Flask. The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code.

However, this is not a high-severity issue, as for an attack like this to work, an attacker must:

Be able to write arbitrary values to the cache
Be able to generate a cache key that will collide with a value being read by the application
Cause the application to read a maliciously-injected value

Any situation where all 3 of those is true is a situation where the application has larger problems; for example, if someone's able to inject malicious cached rendered pages into a Flask app's cache, then they can make the website say literally anything they want, regardless of whether it involves the execution of remote code. Basically, the Pickle vulnerability follows from a website already being extremely vulnerable (due to conditions 1 and 2 being met).

Severity ?

4.2 (Medium)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Flask-Caching"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "1.10.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-33026"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-269",
      "CWE-502"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-05-17T17:25:38Z",
    "nvd_published_at": "2021-05-13T23:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Flask-Cache adds easy cache support to Flask. The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code.\n\nHowever, this is not a high-severity issue, as for an attack like this to work, an attacker must:\n\n1. Be able to write arbitrary values to the cache\n2. Be able to generate a cache key that will collide with a value being read by the application\n3. Cause the application to read a maliciously-injected value\n\nAny situation where all 3 of those is true is a situation where the application has larger problems; for example, if someone\u0027s able to inject malicious cached rendered pages into a Flask app\u0027s cache, then they can make the website say literally anything they want, regardless of whether it involves the execution of remote code. Basically, the Pickle vulnerability follows from a website already being extremely vulnerable (due to conditions 1 and 2 being met).",
  "id": "GHSA-656c-6cxf-hvcv",
  "modified": "2022-09-20T13:31:06Z",
  "published": "2021-06-18T18:33:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33026"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pallets-eco/flask-caching/pull/209#issuecomment-1136397937"
    },
    {
      "type": "WEB",
      "url": "https://github.com/sh4nks/flask-caching/pull/209"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-656c-6cxf-hvcv"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/flask-caching/PYSEC-2021-13.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sh4nks/flask-caching"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Deserialization of Untrusted Data in Flask-Caching"
}

CVE-2021-33026 (GCVE-0-2021-33026)

Vulnerability from cvelistv5 – Published: 2021-05-13 22:51 – Updated: 2024-08-03 23:42

Summary

The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code. NOTE: a third party indicates that exploitation is extremely unlikely unless the machine is already compromised; in other cases, the attacker would be unable to write their payload to the cache and generate the required collision

Severity ?

9.8 (Critical)


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

CWE

Assigner

mitre

References

URL

Tags

	https://github.com/sh4nks/flask-caching/pull/209	x_refsource_MISC
	https://github.com/pallets-eco/flask-caching/pull…	x_refsource_MISC

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "affected": [
          {
            "cpes": [
              "cpe:2.3:a:flask-caching_project:flask-caching:*:*:*:*:*:flask:*:*"
            ],
            "defaultStatus": "unknown",
            "product": "flask-caching",
            "vendor": "flask-caching_project",
            "versions": [
              {
                "lessThanOrEqual": "1.10.1",
                "status": "affected",
                "version": "0",
                "versionType": "custom"
              }
            ]
          }
        ],
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-33026",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-07-19T18:22:56.685627Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-502",
                "description": "CWE-502 Deserialization of Untrusted Data",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-07-19T18:25:49.436Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T23:42:19.075Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/sh4nks/flask-caching/pull/209"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/pallets-eco/flask-caching/pull/209#issuecomment-1136397937"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code. NOTE: a third party indicates that exploitation is extremely unlikely unless the machine is already compromised; in other cases, the attacker would be unable to write their payload to the cache and generate the required collision"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-09-16T22:55:27",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sh4nks/flask-caching/pull/209"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pallets-eco/flask-caching/pull/209#issuecomment-1136397937"
        }
      ],
      "tags": [
        "disputed"
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-33026",
          "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": "** DISPUTED ** The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code. NOTE: a third party indicates that exploitation is extremely unlikely unless the machine is already compromised; in other cases, the attacker would be unable to write their payload to the cache and generate the required collision."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/sh4nks/flask-caching/pull/209",
              "refsource": "MISC",
              "url": "https://github.com/sh4nks/flask-caching/pull/209"
            },
            {
              "name": "https://github.com/pallets-eco/flask-caching/pull/209#issuecomment-1136397937",
              "refsource": "MISC",
              "url": "https://github.com/pallets-eco/flask-caching/pull/209#issuecomment-1136397937"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-33026",
    "datePublished": "2021-05-13T22:51:20",
    "dateReserved": "2021-05-13T00:00:00",
    "dateUpdated": "2024-08-03T23:42:19.075Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

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.

Action not permitted

PYSEC-2021-13

GHSA-656C-6CXF-HVCV

CVE-2021-33026 (GCVE-0-2021-33026)

Tags

Sightings

Nomenclature