https://db.gcve.eu/sightings/feed 2026-05-04T16:37:14.718617+00:00 Vulnerability-Lookup info@gcve.eu python-feedgen Contains only the most 10 recent sightings. https://db.gcve.eu/sighting/7c5771fa-4f36-4e23-8b42-287973e3f7c7/export 2026-05-04T16:37:15.074447+00:00 cedric http://db.gcve.eu/user/cedric {"uuid": "7c5771fa-4f36-4e23-8b42-287973e3f7c7", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "2a075640-a300-48a4-bb44-bc6130783b9b", "vulnerability": "CVE-2023-40021", "type": "seen", "source": "https://t.me/cibsecurity/68698", "content": "\u203c CVE-2023-40021 \u203c\n\nOppia 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.\n\n\ud83d\udcd6 Read\n\nvia \"National Vulnerability Database\".", "creation_timestamp": "2023-08-17T00:36:51.000000Z"} 2023-08-17T00:36:51+00:00