CVE-2025-48927: Smarsh Telemessage Info Disclosure Flaw

CVE-2025-48927 Overview

CVE-2025-48927 is an Information Exposure vulnerability affecting the Smarsh TeleMessage service through 2025-05-05. The vulnerability stems from an Insecure Default Configuration where Spring Boot Actuator is configured with an exposed heap dump endpoint at a /heapdump URI. This misconfiguration allows unauthenticated attackers to access sensitive memory contents, potentially exposing credentials, session tokens, and other confidential data stored in the Java Virtual Machine heap.

This vulnerability was actively exploited in the wild in May 2025 and has been added to the CISA Known Exploited Vulnerabilities (KEV) catalog, indicating significant real-world risk.

Critical Impact

Unauthenticated attackers can retrieve heap dumps containing sensitive information including credentials, encryption keys, and user data from TeleMessage servers via a publicly accessible endpoint.

Affected Products

• Smarsh TeleMessage (versions through 2025-05-05)

Discovery Timeline

• 2025-05-28 - CVE-2025-48927 published to NVD
• 2025-11-05 - Last updated in NVD database

Technical Details for CVE-2025-48927

Vulnerability Analysis

This vulnerability is classified under CWE-1188 (Insecure Default Initialization of Resource), which describes scenarios where software initializes or sets a resource with a default value that is intended to be changed by an administrator but the default value is not secure.

The TeleMessage service utilizes Spring Boot Actuator, a popular framework component that provides production-ready features for monitoring and managing applications. When improperly configured, Actuator endpoints can expose sensitive operational data. In this case, the /heapdump endpoint was accessible without authentication, allowing any network-connected attacker to download a complete memory dump of the running Java application.

Heap dumps contain a snapshot of all objects in the JVM memory at the time of capture. This typically includes plaintext credentials, API keys, session tokens, decrypted messages, database connection strings, and other sensitive runtime data that applications process but don't necessarily persist to storage.

Root Cause

The root cause is the insecure default configuration of Spring Boot Actuator endpoints in the TeleMessage service. By default, Spring Boot Actuator endpoints should be secured and require authentication, but the TeleMessage deployment exposed the /heapdump endpoint without proper access controls. This represents a failure to implement security best practices when deploying Spring Boot applications in production environments.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by simply sending an HTTP GET request to the /heapdump endpoint on an exposed TeleMessage server. The response contains a binary heap dump file that can be analyzed offline using tools like Eclipse Memory Analyzer (MAT) or VisualVM to extract sensitive information.

The attack is trivial to execute once an exposed endpoint is discovered, as documented in the Wired article on the TeleMessage hack which reported that the exploitation took approximately 20 minutes. Attackers can use automated scanning tools to identify exposed Actuator endpoints across the internet, then systematically download heap dumps from vulnerable instances.

Detection Methods for CVE-2025-48927

Indicators of Compromise

• HTTP GET requests to /heapdump, /actuator/heapdump, or similar Actuator endpoint paths from external IP addresses
• Large outbound data transfers from web servers corresponding to heap dump file sizes (often hundreds of MB to several GB)
• Access logs showing successful 200 responses to Actuator endpoints from unauthorized sources
• Unusual authentication failures or credential abuse following heap dump access (indicating extracted credentials in use)

Detection Strategies

• Implement web application firewall (WAF) rules to block or alert on requests to Spring Boot Actuator endpoints from untrusted sources
• Configure intrusion detection systems (IDS) to monitor for access patterns targeting common Actuator paths (/actuator/*, /heapdump, /env, /configprops)
• Deploy endpoint detection and response (EDR) solutions to identify Java processes serving requests to sensitive management endpoints
• Conduct regular vulnerability assessments to identify exposed Actuator endpoints across your infrastructure

Monitoring Recommendations

• Enable comprehensive access logging on all web servers and reverse proxies to capture requests to management endpoints
• Set up real-time alerts for any access to /heapdump or other sensitive Actuator endpoints
• Monitor for anomalous credential usage that may indicate credentials extracted from heap dumps are being exploited
• Implement network traffic analysis to detect large binary file downloads from application servers

How to Mitigate CVE-2025-48927

Immediate Actions Required

• Immediately disable or restrict access to the /heapdump endpoint and all other Spring Boot Actuator endpoints on production TeleMessage deployments
• Rotate all credentials, API keys, and secrets that may have been stored in memory on affected systems
• Review access logs to identify any unauthorized access to Actuator endpoints and assess potential data exposure
• Implement network-level controls to restrict access to management endpoints to authorized administrative networks only

Patch Information

Organizations should update TeleMessage to versions released after 2025-05-05 that address this misconfiguration. Contact Smarsh for specific patch information and remediation guidance. Until patches are applied, implement the workarounds described below to mitigate exposure.

For reference, this vulnerability is tracked in the CISA Known Exploited Vulnerabilities Catalog.

Workarounds

• Disable all non-essential Actuator endpoints in Spring Boot configuration by setting management.endpoints.enabled-by-default=false
• Restrict Actuator endpoint access to localhost only by configuring management.server.address=127.0.0.1
• Implement Spring Security to require authentication for all Actuator endpoints
• Place Actuator endpoints behind a reverse proxy that requires VPN or internal network access
• Use firewall rules to block external access to Actuator management ports

# Spring Boot application.properties configuration to secure Actuator endpoints
# Disable all endpoints by default
management.endpoints.enabled-by-default=false

# Only enable health endpoint for load balancer checks
management.endpoint.health.enabled=true

# Restrict management interface to localhost only
management.server.address=127.0.0.1
management.server.port=8081

# Require authentication for any enabled endpoints
management.endpoints.web.exposure.include=health