How severe is CVE-2021-20147?

CVE-2021-20147 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-20147 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20147?

CVE-2021-20147 primarily affects Zohocorp Manageengine Adselfservice Plus. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20147?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-20147 published?

CVE-2021-20147 was published on 2022-01-03 and last updated on 2026-06-17.

CVE-2021-20147

CVE-2021-20147 is a medium-severity vulnerability in Zohocorp Manageengine Adselfservice Plus with a CVSS 3.x base score of 5.3. 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-203.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-203
Affected product: Zohocorp Manageengine Adselfservice Plus
Published: 2022-01-03
Last modified: 2026-06-17

Description

ManageEngine ADSelfService Plus below build 6116 contains an observable response discrepancy in the UMCP operation of the ChangePasswordAPI. This allows an unauthenticated remote attacker to determine whether a Windows domain user exists.

Frequently asked questions

What is CVE-2021-20147?: ManageEngine ADSelfService Plus below build 6116 contains an observable response discrepancy in the UMCP operation of the ChangePasswordAPI. This allows an unauthenticated remote attacker to determine whether a Windows domain user exists.
How severe is CVE-2021-20147?: CVE-2021-20147 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-20147 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20147?: CVE-2021-20147 primarily affects Zohocorp Manageengine Adselfservice Plus. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20147?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20147 published?: CVE-2021-20147 was published on 2022-01-03 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2021-52

Affected products (18)

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:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6104:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6105:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6106:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6107:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6108:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6109:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6110:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6111:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6112:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6113:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6114:*:*:*:*:*:*
cpe:2.3:a:zohocorp:manageengine_adselfservice_plus:6.1:6115:*:*:*:*:*:*

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.
CVE-2023-35854 — Critical (CVSS 9.8): Zoho ManageEngine ADSelfService Plus through 6113 has an authentication bypass that can be exploited to steal the…
CVE-2022-47966 — Critical (CVSS 9.8): Multiple Zoho ManageEngine on-premise products, such as ServiceDesk Plus through 14003, allow remote code execution due…
CVE-2021-37422 — Critical (CVSS 9.8): Zoho ManageEngine ADSelfService Plus 6111 and prior is vulnerable to SQL Injection while linking the databases.
CVE-2021-37423 — Critical (CVSS 9.8): Zoho ManageEngine ADSelfService Plus 6111 and prior is vulnerable to linked applications takeover.
CVE-2021-40539 — Critical (CVSS 9.8): Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with…

All CVEs affecting Zohocorp Manageengine Adselfservice Plus →

Other CWE-203 (Observable Discrepancy) vulnerabilities

CVE-2019-25337 — Critical (CVSS 9.8): OwnCloud 8.1.8 contains a username enumeration vulnerability that allows remote attackers to discover user accounts by…
CVE-2026-23519 — Critical (CVSS 9.8): RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in…
CVE-2025-27667 — Critical (CVSS 9.8): Vasion Print (formerly PrinterLogic) before Virtual Appliance Host 22.0.843 Application 20.0.1923 allows Administrative…
CVE-2024-25714 — Critical (CVSS 9.8): In Rhonabwy through 1.1.13, HMAC signature verification uses a strcmp function that is vulnerable to side-channel…
CVE-2024-25191 — Critical (CVSS 9.8): php-jwt 1.0.0 uses strcmp (which is not constant time) to verify authentication, which makes it easier to bypass…
CVE-2024-25190 — Critical (CVSS 9.8): l8w8jwt 2.2.1 uses memcmp (which is not constant time) to verify authentication, which makes it easier to bypass…

Browse all CWE-203 (Observable Discrepancy) vulnerabilities →