CVE-2021-26620Network attack vector

Unauthenticated account disclosure via shared-folder enumeration

Published Mar 25, 2022 · Updated Aug 3, 2024

Improper authentication in EFM Networks ipTIME NAS firmware before 1.4.82 allows remote attackers to disclose NAS user information. The file-sharing service returns folder lists without authentication, and default Home.[user ID] folder names reveal account identifiers. The password-change flow requires no existing password and exposes the new password in plaintext traffic, enabling account compromise and access to server data.

CVSS severity7.5
High
EPSS probability1.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in EFM Networks ipTIME NAS firmware before 1.4.82 allows remote attackers to disclose NAS user information. The file-sharing service returns folder lists without authentication, and default Home.[user ID] folder names reveal account identifiers. The password-change flow requires no existing password and exposes the new password in plaintext traffic, enabling account compromise and access to server data.

The record

CVE
CVE-2021-26620
Published
Mar 25, 2022
Updated
Aug 3, 2024
Vendor
EFM Networks
Product
ipTIME NAS
Classifications
CWE-287, T1135, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2022CVE 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <1.4.82

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EFM Networks · ipTIME NASversion=unspecified <1.4.82

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5KrCERT/CCCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1135Network Share Discovery
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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