CVE-2021-27963Public exploitNetwork attack vector

Unauthenticated SuperAdmin creation via unguarded saveUser endpoint

Published Mar 5, 2021 · Updated Aug 3, 2024

Missing authentication in SonLogger before 6.4.1 allows remote attackers to create accounts with SuperAdmin privileges. The /User/saveUser handler accepts an attacker-supplied profile and account credentials in a POST body without validating any authentication or session header. Network reachability alone is sufficient, and the created account grants administrative access and exposes application and user information.

CVSS severity8.2
High
EPSS probability2.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in SonLogger before 6.4.1 allows remote attackers to create accounts with SuperAdmin privileges. The /User/saveUser handler accepts an attacker-supplied profile and account credentials in a POST body without validating any authentication or session header. Network reachability alone is sufficient, and the created account grants administrative access and exposes application and user information.

The record

CVE
CVE-2021-27963
Published
Mar 5, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-306, T1136
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 5, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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

8.2NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
6.4NVDAV:N/AC:L/Au:N/C:P/I:P/A:N

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.

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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 exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1136Create Account

Public exploit references

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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