CVE-2023-28290Network attack vector

Session data disclosure via certificate serial reuse

Published May 9, 2023 · Updated Jul 10, 2025

Certificate validation flaw in Microsoft Remote Desktop app before 10.2.3006 allows remote attackers to intercept session data. The client remembers only a saved self-signed certificate serial number, so a forged certificate reusing that serial passes later identity comparison. Exploitation requires user interaction to save the original certificate and a network position permitting certificate substitution, exposing confidentiality without reported integrity or availability impact.

CVSS severity5.3
Medium
EPSS probability1.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Certificate validation flaw in Microsoft Remote Desktop app before 10.2.3006 allows remote attackers to intercept session data. The client remembers only a saved self-signed certificate serial number, so a forged certificate reusing that serial passes later identity comparison. Exploitation requires user interaction to save the original certificate and a network position permitting certificate substitution, exposing confidentiality without reported integrity or availability impact.

The record

CVE
CVE-2023-28290
Published
May 9, 2023
Updated
Jul 10, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Jul 10, 2025Record 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

5.3Microsoft CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:R/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

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

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Your stack

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