CVE-2021-37417

Zoho ManageEngine ADSelfService Plus version 6103 and prior allows CAPTCHA bypass due to improper parameter validation.

Published: 2021-08-30 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-37417 is rated High Risk (71.1/100): CVSS Critical severity, with high exploitation likelihood (EPSS 4.75%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

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-2021-37417

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 2026-06-23 4.60% 4.75% +0.15%
2 2026-06-15 17.10% 4.60% -12.50%
3 2026-05-30 — 17.10% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-37417

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:N)
No account or special rights needed—anonymous or random user is enough.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/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:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-37417

Affected software / configurations for CVE-2021-37417

Vendor Product Version Raw CPE
zohocorp manageengine_adselfservice_plus < 6.1 cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:*:*:*:*:*:*:*:*
zohocorp manageengine_adselfservice_plus 6.1 cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:-:*:*:*:*:*:*
zohocorp manageengine_adselfservice_plus 6.1 cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6100:*:*:*:*:*:*
zohocorp manageengine_adselfservice_plus 6.1 cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6101:*:*:*:*:*:*
zohocorp manageengine_adselfservice_plus 6.1 cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6102:*:*:*:*:*:*
zohocorp manageengine_adselfservice_plus 6.1 cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6103:*:*:*:*:*:*

References for CVE-2021-37417

URL Tags
https://blog.stmcyber.com/vulns/cve-2021-37417/ Release Notes Third Party Advisory
cvelogic Threat Intelligence