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CriticalCISA KEVExploited in the wildPublic exploit

Microsoft SharePoint Remote Code Execution Vulnerability

IdentifiersCVE-2019-0604CWE-20· Improper Input Validation

CVE-2019-0604 is a critical remote code execution vulnerability in Microsoft SharePoint. According to the provided content, the flaw exists because SharePoint fails to properly check the source markup of an application package. Microsoft’s description states that successful exploitation requires uploading a specially crafted SharePoint application package to an affected SharePoint server. The content also notes reporting that the issue involves an XML deserialization component within SharePoint, and that exploitation in the wild commonly resulted in deployment of ASPX web shells such as China Chopper, AntSword variants, and other custom web shells. Successful exploitation allows arbitrary code execution in the security context of the SharePoint application pool and the SharePoint server farm account.

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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 enables remote arbitrary code execution on vulnerable SharePoint servers. In observed intrusions, attackers used the vulnerability for initial access, installation of persistent web shells, credential harvesting, internal reconnaissance, lateral movement, email theft, and follow-on malware deployment. The content specifically links exploitation to espionage activity, ransomware campaigns, destructive operations, and long-term persistence on government and enterprise networks. Because execution occurs in the context of SharePoint service accounts, compromise can extend beyond the web server into the broader SharePoint farm and internal network.

Mitigation

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

In addition to patching, the content recommends not exposing on-premises-only SharePoint instances directly to the internet where possible. Organizations that were exposed prior to remediation should investigate for compromise, especially for ASPX web shells under SharePoint paths, anomalous POST requests to SharePoint layout pages, suspicious child processes from SharePoint/IIS, credential theft activity, and persistence artifacts. If exploitation is suspected, remove web shells, rotate compromised credentials and service account secrets, and perform broader incident response because attackers commonly retain access after initial exploitation.

Remediation

Patch, then assume compromise.

Apply Microsoft’s security updates for CVE-2019-0604 to all affected SharePoint installations. The content indicates Microsoft re-released the initial security update after the original patch did not fully prevent exploitation, so organizations should ensure the corrected/latest update level is installed rather than relying on the first March 2019 release alone. Verify all affected SharePoint versions in the environment, including on-premises deployments, are fully patched.
PUBLIC EXPLOITS

Exploits

3 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos (1 hidden).

VALID 3 / 4 TOTALView more in app
CVE-2019-0604MaturityPoCVerified exploit

This repository contains a Python exploit script (cve-2019-0604-exp.py) targeting Microsoft SharePoint servers vulnerable to CVE-2019-0604, a remote code execution flaw. The exploit works by sending crafted requests to the SharePoint Picker.aspx endpoint, leveraging the vulnerability to upload a web shell (ua.aspx) to the server. Once the shell is uploaded, the script attempts to access it to verify successful exploitation. The main file is a standalone Python script, and the only other file is a README with references to further documentation. The exploit requires the attacker to provide the base URL of the target SharePoint instance. The script is operational and provides a working web shell if the target is vulnerable.

k8gegeDisclosed Jun 26, 2019pythonnetwork
CVE-2019-0604MaturityPoCVerified exploit

This repository is a proof-of-concept exploit for CVE-2019-0604, a remote code execution vulnerability in Microsoft SharePoint. The main code is in 'ConsoleApplication1/ConsoleApplication1/Program.cs', a C# console application that demonstrates how a malicious XAML file (t.xml) can be used to trigger code execution via SharePoint's deserialization of XAML. The exploit leverages the 'ObjectDataProvider' in XAML to launch arbitrary commands (e.g., 'cmd.exe /c calc'). The repository includes the XAML payload (t.xml) and the C# code that loads and executes it, simulating the vulnerable SharePoint behavior. No network endpoints or hardcoded IPs are present, but the attack vector is network-based, targeting SharePoint servers that process attacker-supplied XAML. The exploit is a POC and does not include weaponized or automated exploitation scripts.

linhlhqDisclosed Mar 23, 2019csharpxamlnetwork
weaponized-0604MaturityPoCVerified exploit

This repository is a weaponized exploit for CVE-2019-0604, a critical remote code execution vulnerability in Microsoft SharePoint. The main exploit logic is in 'exploit.py', which automates the exploitation process, supporting both direct command execution and file upload (such as webshells) to the target SharePoint server. The exploit can operate in both authenticated and unauthenticated modes, depending on the target's configuration. It supports out-of-band (OOB) exfiltration of command output via DNS or HTTP channels, integrating with services like Burp Collaborator or requestbin.net. The payloads are serialized XAML objects that trigger the vulnerability, and the repository includes helper scripts for request parsing, payload generation, and OOB data handling. The structure is modular, with separate files for SharePoint-specific payload crafting ('sharepointkit.py'), OOB handling ('oob/collab_handler.py', 'oob/decoder.py'), and a sample PowerShell webshell ('oob/payload.ps1'). The exploit is operational and can be used to gain remote code execution, upload arbitrary files, and retrieve output from the target system.

Gh0st0neDisclosed Apr 22, 2021pythonpowershellnetwork
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 Enterprise Serverapplication
Microsoft CorporationSharepoint Foundationapplication
Microsoft CorporationSharepoint Serverapplication

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What this page doesn’t show

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Exposure mapping

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Threat actor evidence12

Every observed campaign linking this CVE to a named adversary.

Associated malware12

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 activity

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