Schule is open-source school management system software. The generateOTP() function generates a 4-digit numeric One-Time Password (OTP). Prior to version 1.0.1, even if a secure random number generator is used, the short length and limited range (1000–9999) results in only 9000 possible combinations. This small keyspace makes the OTP highly vulnerable to brute-force attacks, especially in the absence of strong rate-limiting or lockout mechanisms. Version 1.0.1 fixes the issue.
https://github.com/schule111/Schule/security/advisories/GHSA-6c48-67xx-vqgc
https://github.com/schule111/Schule/commit/cd53abbea93943f2c60a5281d45bebadc57636b7
Published: 2025-05-22
Updated: 2025-05-23
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: High
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00041