CVE-2025-48928: Smarsh TeleMessage Information Disclosure

CVE-2025-48928 Overview

CVE-2025-48928 affects the TeleMessage service, a Smarsh product used to archive messaging content. The vulnerability exists in the JSP-based application, where heap content behaves like a core dump. Passwords previously transmitted over HTTP remain resident in this heap dump. Attackers who access the heap contents can extract credentials sent in prior sessions. CISA added the vulnerability to its Known Exploited Vulnerabilities catalog, and public reporting confirms exploitation in May 2025 against TeleMessage customers, including U.S. federal officials.

Critical Impact
Passwords transmitted over HTTP are recoverable from JSP heap memory, enabling account compromise and downstream access to archived communications.

Affected Products

Smarsh TeleMessage service through 2025-05-05
TeleMessage JSP application components exposing heap content
TeleMessage Signal, WhatsApp, Telegram, and WeChat archiving variants running the affected service

Discovery Timeline

2025-05-05 - Exploitation observed in the wild against TeleMessage service
2025-05-28 - CVE-2025-48928 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-48928

Vulnerability Analysis

The TeleMessage service runs as a JavaServer Pages (JSP) application. During operation, the Java Virtual Machine (JVM) retains request data in heap memory. When the heap contents are exposed through an accessible endpoint, the returned data resembles a process core dump. Sensitive values processed by prior requests, including plaintext passwords, remain present in that memory region.

The issue maps to two Common Weakness Enumeration entries: [CWE-528] (Exposure of Core Dump File to an Unauthorized Control Sphere) and [CWE-552] (Files or Directories Accessible to External Parties). Public reporting by Wired describes attackers extracting the heap dump within roughly 20 minutes of probing the service. The exposed material included credentials for the TeleMessage management interface.

Root Cause

The root cause is twofold. First, the application accepts credentials over cleartext HTTP, which leaves them in Java heap objects. Second, the deployed JSP application exposes a diagnostic-style endpoint that returns heap content without authentication. The combination allows unauthenticated retrieval of memory that still contains credential material from prior sessions.

Attack Vector

An attacker requests the exposed heap dump endpoint on the TeleMessage service. The server returns a memory image containing string data from recent requests. The attacker then parses the dump for password patterns and reuses recovered credentials against the TeleMessage management console. No authentication is required to obtain the heap content, and the CVSS vector describes the attack surface as local to the service's exposed interface.

No verified proof-of-concept code has been published. See the Wired reporting on the TeleMessage compromise for reported exploitation details.

Detection Methods for CVE-2025-48928

Indicators of Compromise

HTTP requests to JSP diagnostic or heap-dump endpoints on TeleMessage hosts, particularly requests returning large binary or text payloads
Authentication events on the TeleMessage management console originating from previously unseen IP addresses shortly after heap-dump retrieval
Outbound transfers of unusually large responses from the TeleMessage web tier to external addresses

Detection Strategies

Review web server access logs for requests to paths that return application heap content, and correlate response sizes with baseline JSP responses
Alert on cleartext HTTP POSTs to TeleMessage login endpoints, since credentials submitted over HTTP are the source of exposed material
Correlate successful TeleMessage administrative logins with prior anomalous read requests against the same host

Monitoring Recommendations

Ingest TeleMessage web tier, JVM, and reverse-proxy logs into a centralized SIEM for retention and correlation
Monitor for repeated scanning patterns against /heapdump, /actuator, or similar diagnostic paths on Java web applications
Track credential reuse across TeleMessage, Signal-linked accounts, and integrated archiving destinations

How to Mitigate CVE-2025-48928

Immediate Actions Required

Contact Smarsh for the current fixed release of the TeleMessage service and apply vendor-provided updates
Rotate all TeleMessage administrative, service, and integration credentials that may have transited the affected system
Disable or block external access to any diagnostic, heap-dump, or debug endpoints exposed by the JSP application
Enforce HTTPS for all TeleMessage authentication and administrative traffic, and disable HTTP listeners

Patch Information

Smarsh has not published a public advisory URL in the referenced NVD record. Customers should engage Smarsh support directly for the fixed build and confirm remediation of both the heap exposure and the cleartext HTTP credential path. CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog, which requires federal agencies to remediate on a defined schedule.

Workarounds

Place the TeleMessage service behind a reverse proxy that blocks access to diagnostic and heap-dump URIs
Terminate TLS at the proxy and redirect all HTTP traffic to HTTPS to prevent credentials from entering heap memory in cleartext form
Restrict management interface access to a bastion or VPN network segment and require multi-factor authentication for administrators
Reduce JVM heap dump generation and disable any framework debug consoles in production deployments

bash

# Example NGINX configuration to block heap and diagnostic endpoints
location ~* /(heapdump|actuator|debug|dump) {
    deny all;
    return 403;
}

server {
    listen 80;
    return 301 https://$host$request_uri;
}