CVE-2021-37423Network attack vector

Password sync takeover via unauthenticated agent replacement

Published Sep 10, 2021 · Updated Aug 4, 2024

Authentication bypass in Zoho ManageEngine ADSelfService Plus 6123 and earlier allows remote attackers to take over Password Sync Agent functions. The server accepts unauthenticated requests that delete the registered Password Sync Agent and replace it with an attacker-controlled agent without validating an access key. Network access to the server is sufficient, and the fake agent gains every Password Sync Agent capability, including synchronization of Active Directory passwords and account changes.

CVSS severity9.8
Critical
EPSS probability2.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Zoho ManageEngine ADSelfService Plus 6123 and earlier allows remote attackers to take over Password Sync Agent functions. The server accepts unauthenticated requests that delete the registered Password Sync Agent and replace it with an attacker-controlled agent without validating an access key. Network access to the server is sufficient, and the fake agent gains every Password Sync Agent capability, including synchronization of Active Directory passwords and account changes.

The record

CVE
CVE-2021-37423
Published
Sep 10, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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