CVE-2021-29659Network attack vector

Authenticated account enumeration via whitespace-only sharee query

Published May 20, 2021 · Updated Aug 3, 2024

Incorrect access control in ownCloud 10.7 allows remote authenticated users to enumerate all instance accounts via the sharing API. The sharee autocomplete endpoint treats three whitespace characters as a valid three-character query, bypassing the intended name-or-email match and returning every account. Any authenticated account can trigger the disclosure; on large instances, the same request can also impose elevated server load.

CVSS severity6.5
Medium
EPSS probability1.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect access control in ownCloud 10.7 allows remote authenticated users to enumerate all instance accounts via the sharing API. The sharee autocomplete endpoint treats three whitespace characters as a valid three-character query, bypassing the intended name-or-email match and returning every account. Any authenticated account can trigger the disclosure; on large instances, the same request can also impose elevated server load.

The record

CVE
CVE-2021-29659
Published
May 20, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-200, T1087
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.0NVDAV:N/AC:L/Au:S/C:P/I:N/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1087Account Discovery

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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