SARA / Free Tools / CVE / CVE-2023-40021

CVE-2023-40021 — Oppia is an online learning platform

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

CVSS
5.3 MEDIUM
EPSS
17.00% (top 61.60%)
CWE
CWE-203, CWE-208
Published
2023-08-16T20:25:22.726Z
Last modified
2024-10-03T13:37:09.373Z
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

01What is this vulnerability?

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…

02Affected products

VendorProductVersions
oppiaoppia>= 1.1.0, < 3.3.2-hotfix-2

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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