Cyber Resilience

CVE-2023-25403

HighPublic PoC

Published: 03 March 2023

Published
03 March 2023
Modified
07 March 2025
KEV Added
—
Patch
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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0021 42.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-25403 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Yf-Exam Project Yf-Exam. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 42.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

CleverStupidDog yf-exam v 1.8.0 is vulnerable to Authentication Bypass. The program uses a fixed JWT key, and the stored key uses username format characters. Any user who logged in within 24 hours. A token can be forged with his username…

more

to bypass authentication.

CWE(s)
CWE-639

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

yf-exam project
yf-exam
1.8.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AC-24 Access Control Decisions
addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

AC-3 Access Enforcement
addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

References