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HighCISA KEVExploited in the wildPublic exploit

Remote Code Execution in Microsoft Office SharePoint

IdentifiersCVE-2025-49704CWE-94· Improper Control of Generation of…

CVE-2025-49704 is a remote code execution vulnerability in on-premises Microsoft Office SharePoint / SharePoint Server. The provided content describes it as an improper control of code generation ('code injection') issue and also references insecure deserialization of untrusted data as the underlying exploitation mechanism in some reporting. Microsoft identified it as part of the SharePoint 'ToolShell' exploit chain, where it was paired with CVE-2025-49706 and later related bypass variants CVE-2025-53770 and CVE-2025-53771. Observed exploitation targeted internet-facing on-premises SharePoint servers, including via POST requests to the SharePoint ToolPane endpoint. Successful exploitation was followed by deployment of malicious ASPX payloads such as spinstall0.aspx to execute attacker-controlled code and retrieve SharePoint ASP.NET MachineKey material. The issue affects on-premises SharePoint Server deployments and does not affect SharePoint Online in Microsoft 365.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows remote execution of attacker-controlled code on vulnerable on-premises SharePoint servers. In observed intrusions, this enabled deployment of web shells, theft of SharePoint ASP.NET MachineKey material, command execution in the IIS worker process (w3wp.exe), persistence establishment, credential dumping, lateral movement, and follow-on ransomware deployment including Warlock. Microsoft reported active exploitation by multiple threat actors, including Linen Typhoon, Violet Typhoon, and Storm-2603, against internet-facing SharePoint environments.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce or eliminate internet exposure of on-premises SharePoint servers, especially public-facing instances. Enable AMSI in Full Mode with Microsoft Defender Antivirus or equivalent protections, deploy EDR monitoring, and hunt for exploitation artifacts such as POST requests to /_layouts/15/ToolPane.aspx and suspicious ASPX files including spinstall0.aspx, spinstall.aspx, spinstall1.aspx, and spinstall2.aspx. Monitor for abnormal w3wp.exe child processes, MachineKey access, scheduled task creation, IIS component manipulation, credential dumping activity, and lateral movement via PsExec, WMI, or Impacket.

Remediation

Patch, then assume compromise.

Apply Microsoft's security updates for affected on-premises SharePoint versions, including SharePoint Server Subscription Edition, SharePoint Server 2019, and SharePoint Server 2016. The content specifically references Microsoft security update packages that addressed CVE-2025-49704 and later comprehensive updates that also addressed related bypass variants CVE-2025-53770 and CVE-2025-53771. After patching, Microsoft recommended rotating SharePoint ASP.NET machine keys and restarting IIS to invalidate stolen key material and ensure updated components are loaded.
PUBLIC EXPLOITS

Exploits

No valid public exploits. Mallory filtered out 1 candidate as fakes, detection scripts, or README-only repos.

VALID 0 / 1 TOTALView more in app

All candidate exploits were filtered out by Mallory's validation.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationSharepoint Serverapplication
Microsoft CorporationSharepoint Server 2016application
Microsoft CorporationSharepoint Server 2019application

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence25

Every observed campaign linking this CVE to a named adversary.

Associated malware23

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity96

Community discussion across Reddit, Mastodon, and other social sources.