CVE-2023-52951Network attack vector

Credential disclosure via cleartext client transmission

Published Jun 3, 2026 · Updated Jun 3, 2026

Cleartext credential transmission in Synology Note Station Client before 2.2.4-703 allows man-in-the-middle attackers to obtain credentials. Synology has not published the affected protocol, credential field, or client operation that sends the credential without adequate transport protection. Exploitation requires a network position from which traffic between the desktop client and its Synology NAS service can be intercepted, and the reported impact is credential disclosure only.

CVSS severity5.9
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cleartext credential transmission in Synology Note Station Client before 2.2.4-703 allows man-in-the-middle attackers to obtain credentials. Synology has not published the affected protocol, credential field, or client operation that sends the credential without adequate transport protection. Exploitation requires a network position from which traffic between the desktop client and its Synology NAS service can be intercepted, and the reported impact is credential disclosure only.

The record

CVE
CVE-2023-52951
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Synology
Product
Synology Note Station Client
Classifications
CWE-319, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=* <2.2.4-703

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Synology · Synology Note Station Clientversion=* <2.2.4-703

Published CVSS scores

5.9Synology Inc.CVSS:3.1/AV:N/AC:H/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.

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

CWE-319Cleartext Transmission of Sensitive Information
T1557Adversary-in-the-Middle

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo