CVE-2023-33160Network attack vector

Authenticated code execution via unchecked generic arguments

Published Jul 11, 2023 · Updated Feb 28, 2025

Deserialization in Microsoft SharePoint Server allows remote authenticated users to execute arbitrary code through crafted ASPX page content. SPPageParserFilter accepts a safe generic control without recursively checking its attacker-chosen type arguments against the Safe Controls list. A valid SharePoint account able to create or upload a custom ASPX page can use a null-terminated type name to invoke an unsafe property converter in the web process.

CVSS severity8.8
High
EPSS probability4.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization in Microsoft SharePoint Server allows remote authenticated users to execute arbitrary code through crafted ASPX page content. SPPageParserFilter accepts a safe generic control without recursively checking its attacker-chosen type arguments against the Safe Controls list. A valid SharePoint account able to create or upload a custom ASPX page can use a null-terminated type name to invoke an unsafe property converter in the web process.

The record

CVE
CVE-2023-33160
Published
Jul 11, 2023
Updated
Feb 28, 2025
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-502, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 28, 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?

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

  1. Affected versionversion=16.0.0 <16.0.5404.1000

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <16.0.5404.1000
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <16.0.10400.20008
Microsoft · Microsoft SharePoint Server Subscription Editionversion=16.0.0 <16.0.16130.20642

Published CVSS scores

8.8Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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