How severe is CVE-2021-37421?

CVE-2021-37421 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-37421 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37421?

CVE-2021-37421 primarily affects Zohocorp Manageengine Adselfservice Plus. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-37421?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-37421 published?

CVE-2021-37421 was published on 2021-08-30 and last updated on 2026-06-17.

CVE-2021-37421

CVE-2021-37421 is a critical-severity vulnerability in Zohocorp Manageengine Adselfservice Plus with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Zohocorp Manageengine Adselfservice Plus
Published: 2021-08-30
Last modified: 2026-06-17

Description

Zoho ManageEngine ADSelfService Plus 6103 and prior is vulnerable to admin portal access-restriction bypass.

Frequently asked questions

What is CVE-2021-37421?: Zoho ManageEngine ADSelfService Plus 6103 and prior is vulnerable to admin portal access-restriction bypass.
How severe is CVE-2021-37421?: CVE-2021-37421 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-37421 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37421?: CVE-2021-37421 primarily affects Zohocorp Manageengine Adselfservice Plus. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-37421?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-37421 published?: CVE-2021-37421 was published on 2021-08-30 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:*:*:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:-:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6100:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6101:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6102:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6103:*:*:*:*:*:*

More vulnerabilities in Zohocorp Manageengine Adselfservice Plus

CVE-2019-3905 — Critical (CVSS 10.0): Zoho ManageEngine ADSelfService Plus 5.x before build 5703 has SSRF.
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