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CriticalCISA KEVExploited in the wildPublic exploit

ToolShell unauthenticated RCE in Microsoft SharePoint Server

IdentifiersCVE-2025-53770CWE-502· Deserialization of Untrusted DataAlso known assharepoint_toolshelltoolshelltoolshell_vulnerability

CVE-2025-53770 is a deserialization of untrusted data vulnerability in on-premises Microsoft SharePoint Server. The flaw affects supported on-prem SharePoint deployments, including SharePoint Server Subscription Edition, SharePoint Server 2019, SharePoint Server 2016, and SharePoint Enterprise Server 2016 as referenced in the provided content. Multiple sources in the content describe the issue as exploitable over the network via SharePoint web endpoints, including ToolPane.aspx, and characterize it as enabling unauthenticated remote code execution. The vulnerability has been referred to publicly as "ToolShell" and has been observed in exploit chains with CVE-2025-53771, with related lineage to previously disclosed CVE-2025-49704/CVE-2025-49706. Post-exploitation activity described in the content includes deployment of ASPX web shells such as spinstall0.aspx and theft of ASP.NET/SharePoint MachineKey material.

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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 can result in remote code execution on the vulnerable SharePoint server and effective compromise of the underlying Windows host. The content indicates attackers can gain access to SharePoint content, file systems, internal configuration, and execute arbitrary commands. Observed real-world follow-on activity includes web shell deployment, theft of cryptographic MachineKey secrets, persistent unauthenticated access even after patching if keys are not rotated, credential dumping, lateral movement, and ransomware deployment. Impact therefore includes full application compromise, host compromise, data theft, persistence, and downstream enterprise compromise.

Mitigation

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

Where immediate patching is not possible, implement Microsoft's interim mitigations from the provided content: enable AMSI integration in SharePoint, ensure Microsoft Defender Antivirus is active and AMSI is configured in Full Mode where supported, and if mitigations cannot be assured, disconnect internet-facing SharePoint servers from the internet until patched. Defenders should also hunt for known indicators such as spinstall0.aspx and related ASPX web shells in SharePoint layouts paths, monitor for suspicious POST requests to ToolPane.aspx, inspect for MachineKey theft, and isolate any suspected compromised server. Patching alone may be insufficient if key material was stolen.

Remediation

Patch, then assume compromise.

Apply Microsoft's latest comprehensive security updates for all affected on-premises SharePoint versions immediately. The content indicates Microsoft released updates for supported SharePoint versions and later comprehensive fixes specifically addressing CVE-2025-53770 and related CVE-2025-53771. Because exploitation in the wild has included theft of MachineKey material and web shell deployment, remediation should not stop at patching: investigate for compromise, remove web shells and other persistence, rotate SharePoint/ASP.NET MachineKeys if compromise is suspected or confirmed, restart IIS as directed by Microsoft guidance, and perform broader incident response on affected hosts and connected systems.
PUBLIC EXPLOITS

Exploits

10 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos (40 hidden).

VALID 10 / 50 TOTALView more in app
CVE-2025-53770MaturityPoCVerified exploit

This repository provides a comprehensive proof-of-concept exploit and analysis toolkit for the SharePoint ToolPane unauthenticated remote code execution vulnerability (CVE-2025-53770), along with related authentication bypass and deserialization flaws (CVE-2025-49706, CVE-2025-53771, CVE-2025-49704). The main exploit (exploit/exploit.py) sends a crafted HTTP POST request to the ToolPane.aspx endpoint, leveraging a chain of vulnerabilities to achieve RCE without authentication. The payload is a base64-encoded, gzipped .NET LosFormatter/TypeConfuseDelegate gadget chain that executes arbitrary commands (e.g., PowerShell or cmd.exe) on the target server. Auxiliary scripts include a scanner (scanner/scanner.py) to fingerprint vulnerable SharePoint versions and an analysis tool (analysis/analyse.py) to decode and inspect payloads. The repository also contains a Metasploit module and cURL example for alternative exploitation methods. The exploit targets SharePoint Server 2019 (specific vulnerable versions) and requires only network access to the target. The structure is well-documented, with clear separation between exploitation, scanning, and analysis components.

saladin0x1Disclosed Sep 4, 2025pythonrubynetwork
Toolshell_CVE-2025-53770MaturityPoCVerified exploit

This repository provides a functional exploit for CVE-2025-53770 targeting Microsoft SharePoint. The exploit consists of a Python script (toolshell_exploit.py) that automates the upload of a C# webshell (spinstall0.aspx) to a vulnerable SharePoint instance. The attacker must supply valid __VIEWSTATE, __VIEWSTATEGENERATOR, and __EVENTVALIDATION values, which can be obtained from the page source of a SharePoint page. The script uploads the webshell by POSTing these values to the ToolPane.aspx endpoint. Once uploaded, the webshell allows arbitrary command execution via HTTP GET requests to spinstall0.aspx, with the command specified in the 'cmd' query parameter. The exploit also supports delivering a PowerShell reverse shell payload, enabling the attacker to gain an interactive shell on the target. The repository includes a README.md with usage instructions, the Python exploit script, and the C# webshell. The main attack vector is network-based, requiring access to the SharePoint web interface.

GreenForceNetworksDisclosed Jul 22, 2025pythonc#network
CVE-2025-53770MaturityPoCVerified exploit

This repository contains a proof-of-concept exploit for CVE-2025-53770, an unauthenticated remote code execution vulnerability in Microsoft SharePoint Server 2019 (version 16.0.10383.20020) on Windows Server 2019. The exploit targets the ToolPane.aspx endpoint, abusing unsafe .NET deserialization in the Scorecard:ExcelDataSet control. The repository consists of a README.md with detailed vulnerability and usage information, and a Python script (cve-2025-53770.py) that sends a crafted payload to the vulnerable endpoint. The payload is a GZip-compressed, Base64-encoded .NET object embedded in an ASP.NET control, which, when deserialized by the server, can lead to arbitrary code execution. The script extracts and decodes the server's response, saving the result to a local file for further analysis. No authentication is required, and the exploit is network-based. The code is a functional proof-of-concept and does not include a fully weaponized or customizable payload.

Agampreet-SinghDisclosed Aug 7, 2025pythonnetwork
SharePoint-CVE-2025-53770-POCMaturityPoCVerified exploit

This repository provides a C# proof-of-concept tool for building exploit payloads targeting CVE-2025-53770, a deserialization remote code execution vulnerability in Microsoft SharePoint. The main code is in 'OurSharePoint/Program.cs', which takes a Base64-encoded LosFormatter payload (such as one generated by ysoserial.net), wraps it in a custom .NET DataSet with a crafted XML schema and diffgram, serializes it using BinaryFormatter, compresses it with GZip, and outputs a Base64-encoded file ready for use in an exploit scenario. The tool is configurable via command-line arguments for input file, output prefix, and XML element names. The README provides clear instructions and references to public research and a Metasploit implementation. The exploit does not itself deliver the payload to a target but prepares a payload that, when delivered to a vulnerable SharePoint instance, can result in arbitrary code execution. The attack vector is network-based, as exploitation requires sending the payload to a SharePoint deserialization endpoint. No hardcoded network endpoints or IPs are present; the tool is a payload builder, not a delivery mechanism.

Immersive-Labs-SecDisclosed Jul 29, 2025csharpnetwork
CVE-2025-53770MaturityPoCVerified exploit

This repository contains a proof-of-concept Python exploit for CVE-2025-53770, targeting Microsoft SharePoint (version 16.0.0.0). The main file, 'exploit.py', reads a list of target SharePoint URLs from 'target.txt', then for each target, sends a crafted POST request to the '/_layouts/15/ToolPane.aspx?DisplayMode=Edit&a=/ToolPane.aspx' endpoint with a custom payload. The script disables SSL verification and uses a specific Referer header. It analyzes the server's response for a 'CompressedDataTable' value, decodes and decompresses it, and searches for patterns indicating vulnerability. If found, it saves the decompressed data to a file in '/tmp/'. The exploit is a POC and does not provide a shell or advanced payload, but demonstrates the vulnerability and extracts potentially sensitive data from the target. The repository structure is simple, with only a README and the exploit script.

r3xbugbountyDisclosed Jul 28, 2025pythonnetwork
CVE-2025-53770_Raw-HTTP-Request-GeneratorMaturityPoCVerified exploit

This repository contains a Python-based exploit (main.py) and an ASPX webshell payload (pwn.aspx) targeting Microsoft SharePoint servers. The exploit works by encoding the ASPX payload, embedding it in a PowerShell script, and then crafting a complex HTTP POST request to the SharePoint ToolPane.aspx endpoint. If the exploit is successful, the payload is written to a specific location on the target server (spinstall0.aspx). The webshell, when accessed, uses .NET reflection to extract and display sensitive cryptographic keys (ValidationKey, DecryptionKey, etc.) from the server's MachineKey configuration. The repository is structured with a main exploit script and a payload file, and is operational in nature, providing a working attack chain for uploading and executing a webshell on vulnerable SharePoint installations.

BirdsAreFlyingCamerasDisclosed Jul 25, 2025pythonaspxnetwork
OurSharePoint-CVE-2025-53770MaturityPoCVerified exploit

This repository provides a C# proof-of-concept tool for building exploit payloads targeting Microsoft SharePoint deserialization vulnerabilities (CVE-2025-53770). The main code is in 'OurSharePoint/Program.cs', which takes a Base64-encoded LosFormatter payload (typically generated by ysoserial.net), wraps it in a custom .NET DataSet with a crafted XML schema and diffgram, serializes it using BinaryFormatter, compresses it with GZip, and outputs the result as a Base64-encoded file. The tool allows customization of XML element names for obfuscation. The README provides clear instructions and references to public research and Metasploit implementation. The exploit does not itself deliver the payload to a target but prepares a file suitable for use in further exploitation of vulnerable SharePoint instances. No hardcoded network endpoints or IPs are present; the attack vector is network-based, assuming the payload is delivered to a vulnerable SharePoint deserialization sink.

RabbitbongDisclosed Jul 24, 2025csharpxmlnetwork
CVE-2025-53770MaturityPoCVerified exploit

This repository provides a sophisticated Python exploit tool ('divine_absolute.py') targeting CVE-2025-53770, a critical unauthenticated remote code execution vulnerability in Microsoft SharePoint Server (2016, 2019, Subscription Edition, and EOL 2010/2013). The exploit leverages a deserialization flaw in the '/_layouts/15/ToolPane.aspx' endpoint, allowing attackers to deliver .NET deserialization payloads (generated via ysoserial.net) to achieve RCE. The tool features multiple operational modes: reconnaissance (detects SharePoint and endpoint accessibility), exploitation (delivers payloads), and full (combines both with optional aggressive exploitation). Payloads can be customized, including PowerShell AMSI bypasses and out-of-band HTTP/DNS pingbacks for verification. The tool supports advanced evasion (URI suffixes, referer spoofing), adaptive rate limiting, concurrency, and forensic logging. Results are output in JSON for analysis. The repository includes a detailed README, the main exploit script, and a requirements file. The exploit is operational, with customizable payloads and verification mechanisms, and is intended for authorized penetration testing and research only.

exfil0Disclosed Jul 23, 2025pythonnetwork
CVE-2025-53770-ExploitMaturityPoCVerified exploit

This repository provides a comprehensive exploit toolkit for CVE-2025-53770, a .NET deserialization vulnerability in Microsoft SharePoint (on-premises) via the ToolPane.aspx endpoint. The exploit targets authenticated users who can inject a malicious WebPart containing a GZIP-compressed, Base64-encoded serialized .NET object, leading to remote code execution (RCE) on the server. The toolkit consists of: - 'exploit.py': The main exploit script, written in Python, which automates detection of SharePoint, version checking, endpoint validation, and delivery of the malicious payload to the /_layouts/15/ToolPane.aspx endpoint. It supports multi-threaded exploitation, proxying, and batch targeting. - 'YSLosf/Program.cs': A C# utility for generating and deserializing LosFormatter-based .NET payloads. It serializes user-supplied commands or objects, encodes them in Base64, and can also deserialize payloads for testing. - 'compress.py': A helper Python script to GZIP-compress and Base64-encode the serialized payload, preparing it for injection. - 'requirements.txt': Lists Python dependencies for the exploit tool. - 'README.md': Extensive documentation covering usage, payload generation, supported versions, and legal disclaimers. The exploit does not include any built-in reverse shell or web shell payloads; users must generate their own payloads using the provided tools. The attack vector is network-based, requiring authenticated access to a vulnerable SharePoint instance. The main fingerprintable endpoint is '/_layouts/15/ToolPane.aspx', with the 'MSOTlPn_DWP' POST parameter used for payload delivery. The toolkit is intended for security researchers and red teamers to test and demonstrate the vulnerability, not for unauthorized use.

soltanali0Disclosed Jul 21, 2025pythoncsharpnetwork
CVE-2025-53770MaturityPoCVerified exploit

This repository is a proof-of-concept (POC) exploit for Microsoft SharePoint CVE-2025-53770. It contains two files: a README.md describing the exploit and a 'payload' file containing a raw HTTP POST request. The exploit targets the /_layouts/15/ToolPane.aspx endpoint on a SharePoint server, attempting to inject a malicious web part (DWP) via form parameters. The payload includes ASP.NET control registrations and a compressed data table, suggesting an attempt to execute or manipulate server-side code. The exploit is network-based, requiring access to the SharePoint web interface. No detection scripts or fake elements are present; the payload is a direct exploitation attempt. The repository is structured as a minimal POC, with the main exploit logic in the 'payload' file.

kaizensecurityDisclosed Jul 21, 2025httpasp.netnetwork
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

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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

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Threat actor evidence49

Every observed campaign linking this CVE to a named adversary.

Associated malware37

Malware families riding this exploit, with evidence and IOCs.

Detection signatures3

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Vendor-by-vendor mapping

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

Social activity135

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