CVE-2025-53690: Sitecore Experience Commerce RCE Flaw

CVE-2025-53690 Overview

CVE-2025-53690 is a critical deserialization of untrusted data vulnerability affecting Sitecore Experience Manager (XM) and Sitecore Experience Platform (XP). This vulnerability allows remote attackers to perform code injection by exploiting improper handling of serialized data, potentially leading to complete system compromise. The vulnerability has been actively exploited in the wild and has been added to the CISA Known Exploited Vulnerabilities (KEV) catalog.

Critical Impact

This vulnerability enables remote code execution through deserialization attacks, with a changed scope affecting confidentiality, integrity, and availability of affected systems. Organizations running vulnerable Sitecore versions should treat remediation as an emergency priority.

Affected Products

• Sitecore Experience Manager (XM) through version 9.0
• Sitecore Experience Platform (XP) through version 9.0
• Sitecore Experience Commerce
• Sitecore Managed Cloud

Discovery Timeline

• 2025-09-03 - CVE-2025-53690 published to NVD
• 2025-10-30 - Last updated in NVD database

Technical Details for CVE-2025-53690

Vulnerability Analysis

This vulnerability stems from insecure deserialization of untrusted data within Sitecore's web application framework. The flaw is classified under CWE-502 (Deserialization of Untrusted Data), which occurs when an application deserializes data from an untrusted source without proper validation. In the context of Sitecore, this vulnerability is related to ViewState deserialization, a common attack vector in ASP.NET-based applications.

When exploited, an attacker can craft malicious serialized objects that, when deserialized by the vulnerable Sitecore application, execute arbitrary code on the server. The attack has a network-based vector but requires high complexity to successfully exploit. Notably, the vulnerability has a changed scope, meaning successful exploitation can affect resources beyond the vulnerable component's security scope.

Root Cause

The root cause of CVE-2025-53690 lies in the improper validation and sanitization of serialized data before deserialization. Sitecore Experience Manager and Experience Platform through version 9.0 fail to adequately verify that incoming serialized objects originate from trusted sources and contain safe content. This allows attackers to inject malicious serialized payloads that execute arbitrary code when processed by the application's deserialization routines.

Attack Vector

The attack is conducted over the network without requiring authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests containing malicious serialized payloads to a vulnerable Sitecore instance. The ViewState deserialization mechanism processes these payloads, leading to code injection and potential remote code execution.

The attack typically involves:

1. Identifying a vulnerable Sitecore deployment exposed to the network
2. Crafting a malicious serialized object payload designed for .NET deserialization
3. Submitting the payload through ViewState or similar deserialization entry points
4. Achieving code execution when the application deserializes the malicious object

For detailed technical analysis of ViewState deserialization vulnerabilities, refer to the Google Cloud Blog analysis.

Detection Methods for CVE-2025-53690

Indicators of Compromise

• Unusual HTTP POST requests containing abnormally large or encoded ViewState parameters
• Web server logs showing requests with Base64-encoded payloads targeting ASP.NET endpoints
• Unexpected process spawning from IIS worker processes (w3wp.exe)
• Suspicious outbound network connections from web server processes
• Creation of unauthorized files or modifications to web application directories

Detection Strategies

• Monitor web application firewall (WAF) logs for serialization-related attack patterns and suspicious ViewState payloads
• Implement application-level logging to capture deserialization events and anomalies in Sitecore deployments
• Deploy endpoint detection rules to identify unusual process chains originating from web server processes
• Analyze network traffic for indicators of command-and-control communication following potential exploitation
• Review Sitecore application logs for errors related to deserialization failures or unexpected object types

Monitoring Recommendations

• Enable verbose logging on Sitecore instances to capture detailed request information including ViewState content
• Configure SIEM rules to alert on suspicious patterns associated with deserialization attacks targeting ASP.NET applications
• Implement behavioral monitoring for IIS worker processes to detect anomalous child process creation
• Establish baseline network behavior for Sitecore servers and alert on deviations indicating potential exploitation

How to Mitigate CVE-2025-53690

Immediate Actions Required

• Upgrade affected Sitecore Experience Manager and Experience Platform installations to versions beyond 9.0 immediately
• Review the Sitecore Knowledge Base Article KB1003865 for vendor-specific guidance
• Implement network segmentation to limit exposure of vulnerable Sitecore instances
• Deploy web application firewall rules to block known deserialization attack patterns
• Conduct forensic analysis on potentially affected systems to identify signs of prior exploitation

Patch Information

Sitecore has released guidance addressing this vulnerability. Organizations should apply the recommended updates as documented in the Sitecore Knowledge Base Article KB1003865. Given that this vulnerability is listed in the CISA Known Exploited Vulnerabilities Catalog, federal agencies and critical infrastructure operators must prioritize remediation according to CISA timelines.

Workarounds

• Restrict network access to Sitecore administrative interfaces and limit exposure to trusted IP ranges only
• Implement strict input validation and filtering at the web application firewall level to block serialized object payloads
• Disable or restrict ViewState functionality where not operationally required pending permanent patching
• Consider taking vulnerable Sitecore instances offline until patches can be applied if exploitation risk is deemed high
• Enable enhanced logging and monitoring to detect exploitation attempts while awaiting full remediation