CVE-2025-15348: Anritsu ShockLine RCE Vulnerability

CVE-2025-15348 Overview

CVE-2025-15348 is a high-severity insecure deserialization vulnerability affecting Anritsu ShockLine software. This vulnerability allows remote attackers to execute arbitrary code on affected installations by exploiting improper validation during CHX file parsing. User interaction is required to exploit this vulnerability—the target must visit a malicious page or open a malicious file.

The specific flaw exists within the parsing of CHX files. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to execute code in the context of the current process.

Critical Impact

Successful exploitation allows attackers to achieve arbitrary code execution with the privileges of the current user, potentially leading to full system compromise.

Affected Products

• Anritsu ShockLine (specific versions not disclosed)

Discovery Timeline

• 2026-01-23 - CVE-2025-15348 published to NVD
• 2026-01-26 - Last updated in NVD database

Technical Details for CVE-2025-15348

Vulnerability Analysis

This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). The flaw occurs during the parsing of CHX files by Anritsu ShockLine software. When a user opens a specially crafted CHX file, the application deserializes untrusted data without proper validation, allowing an attacker to inject malicious serialized objects.

The attack requires local access and user interaction, meaning the victim must be enticed to open a malicious CHX file. However, once triggered, the vulnerability provides complete control over the execution flow within the context of the current process, enabling arbitrary code execution.

This vulnerability was tracked by the Zero Day Initiative as ZDI-CAN-27833 and disclosed as ZDI-25-1199.

Root Cause

The root cause of this vulnerability lies in the application's failure to properly validate user-supplied data during CHX file parsing. The deserialization process accepts untrusted input without sanitization or type checking, allowing malicious serialized objects to be instantiated. When these objects are processed, they can execute arbitrary code through gadget chains or by directly invoking dangerous methods during the deserialization lifecycle.

Attack Vector

The attack vector requires local access with user interaction. An attacker must craft a malicious CHX file containing a specially constructed serialized payload and deliver it to the victim. This can be accomplished through various social engineering techniques:

• Email attachments containing the malicious CHX file
• Hosting the file on a malicious web page and enticing the user to download and open it
• Placing the file on network shares accessible to the target

When the victim opens the malicious CHX file with Anritsu ShockLine, the deserialization vulnerability triggers, executing the attacker's payload in the context of the current process.

The vulnerability mechanism involves improper handling of serialized data within CHX files. When the application parses these files, it deserializes embedded objects without validating their integrity or type safety. An attacker can embed malicious serialized objects that, upon deserialization, execute arbitrary code through exploitation of available gadget chains in the application's classpath or runtime environment. For technical details, see the Zero Day Initiative Advisory ZDI-25-1199.

Detection Methods for CVE-2025-15348

Indicators of Compromise

• Unexpected CHX files appearing in user download directories or email attachments
• Anomalous process behavior originating from Anritsu ShockLine application processes
• Unusual network connections initiated by ShockLine processes after opening CHX files
• Creation of unexpected child processes by ShockLine applications

Detection Strategies

• Implement file integrity monitoring to detect suspicious CHX files being introduced to the environment
• Monitor process creation events for unusual child processes spawned by Anritsu ShockLine
• Deploy endpoint detection solutions capable of identifying deserialization attack patterns
• Analyze network traffic for anomalous outbound connections following CHX file access

Monitoring Recommendations

• Enable enhanced logging for file access events, particularly for CHX file types
• Configure SIEM rules to correlate CHX file downloads with subsequent suspicious process activity
• Implement behavioral analytics to detect code execution patterns indicative of deserialization exploits
• Monitor for privilege escalation attempts following ShockLine process execution

How to Mitigate CVE-2025-15348

Immediate Actions Required

• Restrict access to CHX files from untrusted sources
• Educate users about the risks of opening CHX files from unknown or untrusted senders
• Implement application whitelisting to prevent unauthorized code execution
• Consider temporarily restricting the use of Anritsu ShockLine until a patch is available

Patch Information

Patch information has not been disclosed in the available data. Users should monitor the Zero Day Initiative Advisory ZDI-25-1199 and Anritsu's official channels for patch availability and remediation guidance. Apply any vendor-provided patches immediately upon release.

Workarounds

• Block or quarantine CHX file attachments at email gateways
• Implement strict file download policies to prevent users from obtaining CHX files from untrusted sources
• Apply principle of least privilege to limit the impact of potential exploitation
• Use network segmentation to isolate systems running Anritsu ShockLine from critical infrastructure

Administrators should configure email security gateways to quarantine or block CHX file attachments and implement endpoint protection policies to restrict execution of potentially malicious content. Consult your security solution documentation for specific configuration steps.