CVE-2023-40021

{"id": "CVE-2023-40021", "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.6}, {"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.6}]}, "published": "2023-08-16T21:15:09.880", "references": [{"url": "https://github.com/oppia/oppia/blob/3a05c3558a292f3db9e658e60e708c266c003fd0/core/controllers/base.py#L964-L990", "tags": ["Product"], "source": "security-advisories@github.com"}, {"url": "https://github.com/oppia/oppia/commit/b89bf808378c1236874b5797a7bda32c77b4af23", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/oppia/oppia/pull/18769", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/oppia/oppia/security/advisories/GHSA-49jp-pjc3-2532", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-203"}]}, {"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-203"}, {"lang": "en", "value": "CWE-208"}]}], "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."}], "lastModified": "2023-08-25T20:08:17.657", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:oppia:oppia:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "87F65B5D-6454-4E3C-A7A5-F1FEEC6DC78C", "versionEndExcluding": "3.3.2", "versionStartIncluding": "1.1.0"}, {"criteria": "cpe:2.3:a:oppia:oppia:3.3.2:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7B0060B6-6E1F-4B0F-8A6B-3437450C94C3"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}