CVE-2025-52636: HCL AION DOS Vulnerability

CVE-2025-52636 Overview

HCL AION is affected by a vulnerability related to the handling of upload size limits. Improper control or validation of upload sizes may allow excessive resource consumption, which could potentially lead to service degradation or denial-of-service conditions under certain scenarios.

Critical Impact

This vulnerability enables resource exhaustion through uncontrolled file upload sizes, potentially causing service degradation or denial-of-service conditions in HCL AION deployments.

Affected Products

• HCL AION

Discovery Timeline

• March 16, 2026 - CVE CVE-2025-52636 published to NVD
• March 17, 2026 - Last updated in NVD database

Technical Details for CVE-2025-52636

Vulnerability Analysis

This vulnerability falls under CWE-400 (Uncontrolled Resource Consumption), a class of weaknesses where software does not properly control the allocation and maintenance of limited resources. In the context of HCL AION, the application fails to adequately validate or enforce limits on uploaded file sizes, creating an avenue for resource exhaustion attacks.

The vulnerability requires local access with high privileges and user interaction to exploit, significantly limiting the attack surface. However, under specific conditions, an attacker who gains the necessary access could leverage improper upload size handling to consume excessive system resources such as disk space, memory, or processing capacity.

Root Cause

The root cause of this vulnerability lies in improper input validation mechanisms within HCL AION's file upload functionality. The application does not adequately enforce upload size restrictions, allowing files that exceed reasonable operational limits to be processed. This lack of boundary checking on upload operations can lead to uncontrolled resource consumption when large or numerous files are uploaded without proper throttling or rejection.

Attack Vector

The attack vector is local, requiring the attacker to have authenticated access to the system with high privileges. The exploitation scenario involves:

1. An authenticated user with elevated privileges initiates file upload operations
2. The application accepts uploads without properly validating size constraints
3. Excessively large uploads consume system resources (disk, memory, CPU)
4. Continued exploitation may lead to service degradation or denial-of-service

The vulnerability requires user interaction for successful exploitation, which combined with the high privilege requirement and local access vector, contributes to the overall low severity rating. The impact is limited to availability with no confidentiality or integrity implications.

Detection Methods for CVE-2025-52636

Indicators of Compromise

• Unusual spikes in disk space consumption associated with upload directories
• Increased memory usage during file upload operations
• Application logs showing repeated large file upload attempts
• System resource monitoring alerts indicating abnormal storage consumption patterns

Detection Strategies

• Monitor upload directory sizes and implement alerts for rapid growth
• Track file upload activity logs for anomalous patterns or unusually large uploads
• Implement resource usage thresholds with automated alerting for HCL AION processes
• Review authentication logs for suspicious high-privilege account activity related to upload functions

Monitoring Recommendations

• Deploy file system monitoring on upload directories to detect abnormal storage consumption
• Configure application performance monitoring (APM) to track resource usage during upload operations
• Establish baseline metrics for normal upload behavior to identify deviations
• Implement log aggregation and analysis for upload-related events in HCL AION

How to Mitigate CVE-2025-52636

Immediate Actions Required

• Review and apply any available patches or updates from HCL Software for AION
• Implement file size restrictions at the web server or application gateway level
• Configure resource quotas for the HCL AION application and associated storage
• Restrict high-privilege account access to only essential personnel

Patch Information

HCL Software has published a knowledge base article addressing this vulnerability. Organizations should consult the HCL Software Knowledge Base Article for specific patch information and remediation guidance.

Workarounds

• Implement upload size limits at the reverse proxy or load balancer level (e.g., Nginx client_max_body_size, Apache LimitRequestBody)
• Configure disk quotas for the upload storage location to prevent resource exhaustion
• Apply rate limiting on upload endpoints to throttle potential abuse
• Enhance monitoring and alerting for resource consumption to enable rapid response to exploitation attempts

# Example: Nginx configuration to limit upload size
# Add to server or location block
client_max_body_size 10M;

# Example: Setting disk quota (Linux)
# Restrict storage quota for the upload directory user
setquota -u aion_upload 500M 1G 0 0 /dev/sda1