CVE-2025-54218: Out-of-Bounds Write Vulnerability in InCopy Leading to Arbitrary Code Execution

Overview

In the world of cybersecurity, few things are as critical as maintaining the integrity of software systems. Today, we delve into a newly identified vulnerability that affects users of Adobe’s InCopy software, specifically versions 20.4, 19.5.4 and earlier. This critical vulnerability, designated as CVE-2025-54218, allows for potential arbitrary code execution which can be exploited by malicious actors to compromise your system or lead to data leakage. The severity of this vulnerability underscores the importance of prompt patch application and diligent system maintenance.

Vulnerability Summary

CVE ID: CVE-2025-54218
Severity: High (CVSS: 7.8)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

InCopy | 20.4 and earlier
InCopy | 19.5.4 and earlier

How the Exploit Works

The root cause of this vulnerability lies in an out-of-bounds write error in the affected versions of InCopy software. This error can be exploited by a malicious actor to execute arbitrary code in the context of the current user. Exploitation, however, requires user interaction, such as opening a maliciously crafted file. Once this file is opened, the out-of-bounds write vulnerability can be triggered, allowing the attacker to potentially take control of the system or cause data leakage.

Conceptual Example Code

A conceptual example of how this vulnerability might be exploited is by creating a malicious InCopy file that triggers the out-of-bounds write when it is opened by the victim. Here is a simplified pseudocode representation of how this might occur:

// Malicious InCopy file
Create InCopy file with out-of-bounds data
Write malicious code in out-of-bounds area
// User's system
User opens malicious InCopy file
InCopy attempts to read out-of-bounds data
Out-of-bounds write triggers
Execution control shifts to malicious code

This example is highly simplified and conceptual, but it serves to illustrate the core mechanics of the exploit.

Mitigation

Users are strongly advised to apply the vendor-supplied patch to fix this vulnerability as soon as possible. As a temporary mitigation, users may employ a Web Application Firewall (WAF) or Intrusion Detection System (IDS). However, these measures only serve to reduce the risk and do not fully eliminate the vulnerability. Therefore, the application of the vendor patch should not be delayed.