CVE-2023-33170Network attack vector

Password-guessing bypass via delayed lockout updates

Published Jul 11, 2023 · Updated May 28, 2026

Security-feature bypass in ASP.NET Core on affected .NET and Visual Studio releases allows remote attackers to make extra password attempts. A race in account-lockout processing fails to update the maximum failed-attempt count immediately when concurrent sign-in failures occur. An exposed application using ASP.NET Core Identity account lockout is required, and exploitation weakens password-guessing controls rather than directly granting account access.

CVSS severity8.1
High
EPSS probability1.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Security-feature bypass in ASP.NET Core on affected .NET and Visual Studio releases allows remote attackers to make extra password attempts. A race in account-lockout processing fails to update the maximum failed-attempt count immediately when concurrent sign-in failures occur. An exposed application using ASP.NET Core Identity account lockout is required, and exploitation weakens password-guessing controls rather than directly granting account access.

The record

CVE
CVE-2023-33170
Published
Jul 11, 2023
Updated
May 28, 2026
Vendor
Microsoft
Product
.NET 6.0
Classifications
CWE-362, T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 2023CVE publishedPublication date reported by the CVE source.
  2. May 28, 2026Record 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=6.0.0 <6.0.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · .NET 6.0version=6.0.0 <6.0.20
Microsoft · Microsoft Visual Studio 2022 version 17.6version=17.6.0 <17.6.5
Microsoft · Microsoft Visual Studio 2022 version 17.4version=17.4.0 <17.4.9
Microsoft · Microsoft Visual Studio 2022 version 17.0version=17.0.0 <17.0.23
Microsoft · Microsoft Visual Studio 2022 version 17.2version=17.2.0 <17.2.17
Microsoft · .NET 7.0version=7.0.0 <7.0.9

Published CVSS scores

8.1MicrosoftCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1110Brute Force

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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