{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.1",
    "cveMetadata": {
        "cveId": "CVE-2023-40021",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2023-08-08T13:46:25.243Z",
        "datePublished": "2023-08-16T20:25:22.726Z",
        "dateUpdated": "2024-10-03T13:37:09.373Z"
    },
    "containers": {
        "cna": {
            "title": "Timing Attack Reveals CSRF Tokens in oppia",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-203",
                            "lang": "en",
                            "description": "CWE-203: Observable Discrepancy",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-208",
                            "lang": "en",
                            "description": "CWE-208: Observable Timing Discrepancy",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "HIGH",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "REQUIRED",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/oppia/oppia/security/advisories/GHSA-49jp-pjc3-2532",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/oppia/oppia/security/advisories/GHSA-49jp-pjc3-2532"
                },
                {
                    "name": "https://github.com/oppia/oppia/pull/18769",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/oppia/oppia/pull/18769"
                },
                {
                    "name": "https://github.com/oppia/oppia/commit/b89bf808378c1236874b5797a7bda32c77b4af23",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/oppia/oppia/commit/b89bf808378c1236874b5797a7bda32c77b4af23"
                },
                {
                    "name": "https://github.com/oppia/oppia/blob/3a05c3558a292f3db9e658e60e708c266c003fd0/core/controllers/base.py#L964-L990",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/oppia/oppia/blob/3a05c3558a292f3db9e658e60e708c266c003fd0/core/controllers/base.py#L964-L990"
                }
            ],
            "affected": [
                {
                    "vendor": "oppia",
                    "product": "oppia",
                    "versions": [
                        {
                            "version": ">= 1.1.0, < 3.3.2-hotfix-2",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2023-08-16T20:25:22.726Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Oppia is an online learning platform. When comparing a received CSRF token against the expected token, Oppia uses the string equality operator (`==`), which is not safe against timing attacks. By repeatedly submitting invalid tokens, an attacker can brute-force the expected CSRF token character by character. Once they have recovered the token, they can then submit a forged request on behalf of a logged-in user and execute privileged actions on that user's behalf. In particular the function to validate received CSRF tokens is at `oppia.core.controllers.base.CsrfTokenManager.is_csrf_token_valid`. An attacker who can lure a logged-in Oppia user to a malicious website can perform any change on Oppia that the user is authorized to do, including changing profile information; creating, deleting, and changing explorations; etc. Note that the attacker cannot change a user's login credentials. An attack would need to complete within 1 second because every second, the time used in computing the token changes. This issue has been addressed in commit `b89bf80837` which has been included in release `3.3.2-hotfix-2`. Users are advised to upgrade. There are no known workarounds for this vulnerability."
                }
            ],
            "source": {
                "advisory": "GHSA-49jp-pjc3-2532",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2024-08-02T18:24:54.658Z"
                },
                "title": "CVE Program Container",
                "references": [
                    {
                        "name": "https://github.com/oppia/oppia/security/advisories/GHSA-49jp-pjc3-2532",
                        "tags": [
                            "x_refsource_CONFIRM",
                            "x_transferred"
                        ],
                        "url": "https://github.com/oppia/oppia/security/advisories/GHSA-49jp-pjc3-2532"
                    },
                    {
                        "name": "https://github.com/oppia/oppia/pull/18769",
                        "tags": [
                            "x_refsource_MISC",
                            "x_transferred"
                        ],
                        "url": "https://github.com/oppia/oppia/pull/18769"
                    },
                    {
                        "name": "https://github.com/oppia/oppia/commit/b89bf808378c1236874b5797a7bda32c77b4af23",
                        "tags": [
                            "x_refsource_MISC",
                            "x_transferred"
                        ],
                        "url": "https://github.com/oppia/oppia/commit/b89bf808378c1236874b5797a7bda32c77b4af23"
                    },
                    {
                        "name": "https://github.com/oppia/oppia/blob/3a05c3558a292f3db9e658e60e708c266c003fd0/core/controllers/base.py#L964-L990",
                        "tags": [
                            "x_refsource_MISC",
                            "x_transferred"
                        ],
                        "url": "https://github.com/oppia/oppia/blob/3a05c3558a292f3db9e658e60e708c266c003fd0/core/controllers/base.py#L964-L990"
                    }
                ]
            },
            {
                "affected": [
                    {
                        "vendor": "oppia",
                        "product": "oppia",
                        "cpes": [
                            "cpe:2.3:a:oppia:oppia:*:*:*:*:*:*:*:*"
                        ],
                        "defaultStatus": "unknown",
                        "versions": [
                            {
                                "version": "1.1.0",
                                "status": "affected",
                                "lessThan": "3.3.2",
                                "versionType": "custom"
                            }
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2024-10-03T13:33:01.578679Z",
                                "id": "CVE-2023-40021",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2024-10-03T13:37:09.373Z"
                }
            }
        ]
    }
}