CVE-2025-21123: Adobe InDesign Buffer Overflow Vulnerability

CVE-2025-21123 Overview

CVE-2025-21123 is a heap-based buffer overflow vulnerability affecting Adobe InDesign Desktop versions ID20.0, ID19.5.1, and earlier. Successful exploitation allows arbitrary code execution in the context of the current user. Exploitation requires user interaction, with a victim opening a malicious InDesign file. Adobe addressed the issue in Adobe Security Advisory APSB25-01. The flaw is tracked under [CWE-122] Heap-based Buffer Overflow and [CWE-787] Out-of-bounds Write.

Critical Impact
Attackers can achieve arbitrary code execution under the current user's privileges by convincing a target to open a crafted InDesign document.

Affected Products

Adobe InDesign Desktop ID20.0
Adobe InDesign Desktop ID19.5.1 and earlier
Runs on Microsoft Windows and Apple macOS

Discovery Timeline

2025-02-11 - CVE-2025-21123 published to NVD
2025-03-03 - Last updated in NVD database

Technical Details for CVE-2025-21123

Vulnerability Analysis

The vulnerability is a heap-based buffer overflow in Adobe InDesign Desktop file parsing routines. When InDesign processes a malformed document, the application writes beyond an allocated heap buffer. The out-of-bounds write corrupts adjacent heap metadata or function pointers reachable from object virtual tables.

A crafted file can shape the heap to control the overwrite target. Attackers chain the corruption with techniques such as return-oriented programming to execute arbitrary code. The process executes the payload with the privileges of the logged-in user, enabling persistence, credential theft, or lateral movement within the user's session.

The issue impacts both Windows and macOS builds of InDesign. Documents are a common business artifact, increasing the likelihood that targeted users will open attachments delivered through phishing or shared collaboration channels.

Root Cause

The root cause is improper bounds checking during parsing of structured fields within InDesign document files. The parser allocates a heap buffer based on attacker-influenced size metadata and then writes content without validating the destination boundary. This pattern matches [CWE-122] and produces the out-of-bounds write described in [CWE-787].

Attack Vector

Exploitation is local and requires user interaction. An attacker delivers a malicious .indd or related InDesign file through email, web download, or a shared workspace. When the victim opens the file in a vulnerable InDesign version, the parser triggers the heap overflow and executes attacker-supplied code.

The vulnerability does not require elevated privileges to exploit. The resulting code runs with the same rights as the user who opened the document. See the Adobe Security Advisory APSB25-01 for vendor technical details.

Detection Methods for CVE-2025-21123

Indicators of Compromise

Unexpected child processes spawned by InDesign.exe on Windows or Adobe InDesign on macOS, such as command shells, scripting hosts, or rundll32.exe.
InDesign process crashes referencing heap corruption in Windows Event Logs or macOS crash reports immediately after opening a document.
Outbound network connections originating from the InDesign process to untrusted hosts.
Newly created executables, scripts, or scheduled tasks following the opening of an InDesign file received from an external source.

Detection Strategies

Monitor process lineage for InDesign spawning interpreters such as powershell.exe, cmd.exe, wscript.exe, bash, or osascript.
Alert on writes by the InDesign process to autorun locations, startup folders, or LaunchAgents directories.
Inspect document delivery channels for .indd, .indt, and .indl files arriving from untrusted senders.
Correlate InDesign crash telemetry with subsequent suspicious file or network activity on the same host.

Monitoring Recommendations

Forward endpoint process, file, and network telemetry to a centralized analytics platform for correlation across hosts.
Track Adobe InDesign version inventory and flag endpoints still running ID20.0 or ID19.5.1 and earlier.
Enable application crash reporting and route InDesign faults to the security operations team for triage.
Apply behavioral analytics to identify anomalous activity originating from creative-suite processes that historically remain isolated.

How to Mitigate CVE-2025-21123

Immediate Actions Required

Update Adobe InDesign to the fixed versions listed in Adobe Security Advisory APSB25-01.
Identify all endpoints running vulnerable InDesign builds and prioritize patching for users who handle external documents.
Block inbound InDesign file types at email and web gateways when business workflows do not require them.
Educate creative and marketing staff on the risk of opening unsolicited InDesign files.

Patch Information

Adobe released fixes for CVE-2025-21123 in security bulletin APSB25-01. Administrators should deploy the updated InDesign builds documented at the Adobe Security Advisory APSB25-01. Both Windows and macOS installers are available through the Adobe Creative Cloud desktop application and Adobe's enterprise deployment tools.

Workarounds

Restrict the opening of InDesign files to documents originating from trusted internal sources until patching is complete.
Run InDesign under standard user accounts to limit the impact of code execution within the user's context.
Enforce attachment sandboxing or detonation for incoming InDesign file types in email security platforms.
Apply application allowlisting to prevent InDesign from spawning interpreters and command shells.

bash

# Inventory InDesign installations on Windows endpoints via PowerShell
Get-CimInstance Win32_Product |
  Where-Object { $_.Name -like 'Adobe InDesign*' } |
  Select-Object Name, Version, InstallDate