CVE-2021-42331 | ShinHer Information Co., LTD. ShinHer StudyOnline System - Improper Authorization-2

The “Study Edit” function of ShinHer StudyOnline System does not perform permission control. After logging in with user’s privilege, remote attackers can access and edit other users’ tutorial schedule by crafting URL parameters.

Published: 2021-10-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-42331 is rated Low Risk (37.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.62%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-42331

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.08% 0.62% +0.54%
2 2023-03-07 1.05% 0.08% -0.97%
3 2022-04-01 — 1.05% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-42331

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.5 [email protected]
5.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 4.9 [email protected]

Weakness enumeration for CVE-2021-42331

Affected software / configurations for CVE-2021-42331

Vendor Product Version Raw CPE
xinheinformation xinhe_teaching_platform_system v2021 cpe:2.3:a:xinheinformation:xinhe_teaching_platform_system:v2021:*:*:*:*:*:*:*

References for CVE-2021-42331

cvelogic Threat Intelligence