CVE-2025-21124 Overview
Adobe InDesign Desktop contains an out-of-bounds read vulnerability affecting versions ID20.0, ID19.5.1, and earlier. The flaw allows an attacker to read sensitive memory outside allocated buffer boundaries when a victim opens a crafted document. Successful exploitation can disclose memory contents that help defeat Address Space Layout Randomization (ASLR) and other memory protections.
The vulnerability requires user interaction. A victim must open a malicious InDesign file for exploitation to succeed. Adobe published this issue in its APSB25-01 security bulletin.
Critical Impact
Memory disclosure from an out-of-bounds read enables attackers to bypass ASLR, weakening defenses against subsequent code execution exploits chained with this flaw.
Affected Products
- Adobe InDesign Desktop version 20.0
- Adobe InDesign Desktop version 19.5.1 and earlier
- Runs on Microsoft Windows and Apple macOS
Discovery Timeline
- 2025-02-11 - CVE-2025-21124 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-21124
Vulnerability Analysis
The vulnerability is classified as an out-of-bounds read [CWE-125] in Adobe InDesign Desktop. The parser reads data past the intended buffer boundary when processing specific structures in an InDesign document. This leaks adjacent process memory back to attacker-controlled code paths or output.
The attack requires local access. A user must open a malicious file delivered through email, shared storage, or a download. The disclosed memory can contain heap addresses, module base offsets, and pointers useful for constructing follow-on exploits.
Root Cause
The root cause is missing or incorrect bounds validation when parsing untrusted document data. InDesign trusts a length field or index derived from the file, then dereferences memory beyond the allocated buffer. Adobe has not published the exact parsing routine involved.
Attack Vector
The attack vector is local file processing. An attacker crafts a malicious .indd or related InDesign document and delivers it through phishing, shared repositories, or supply-chain compromise of design assets. When the victim opens the file in a vulnerable InDesign build, the parser triggers the out-of-bounds read.
The leaked memory does not directly execute code. Attackers typically chain this disclosure with a separate memory corruption bug to defeat ASLR and achieve reliable code execution. See the Adobe InDesign Security Advisory APSB25-01 for vendor guidance.
Detection Methods for CVE-2025-21124
Indicators of Compromise
- Unexpected InDesign process crashes or abnormal termination shortly after opening a document from an untrusted source.
- InDesign documents (.indd, .idml, .indt) received from external senders and opened outside normal design workflows.
- Suspicious child processes or network connections initiated by InDesign.exe following file open events.
Detection Strategies
- Monitor endpoint telemetry for InDesign process anomalies including crashes, unexpected memory allocations, and unusual file handle activity.
- Inspect email and web gateways for InDesign document attachments originating from untrusted senders.
- Correlate file open events with subsequent process behavior to identify exploitation chains that pair memory disclosure with code execution.
Monitoring Recommendations
- Enable endpoint detection and response logging for the InDesign application on Windows and macOS design workstations.
- Track software inventory to identify hosts still running vulnerable InDesign builds 20.0 and 19.5.1 or earlier.
- Alert on execution of scripting engines or shell processes spawned by InDesign.
How to Mitigate CVE-2025-21124
Immediate Actions Required
- Apply the Adobe patches referenced in APSB25-01 to all InDesign Desktop installations.
- Instruct users to avoid opening InDesign documents from untrusted or unverified sources.
- Verify software inventory to confirm no vulnerable versions remain in production or on contractor workstations.
Patch Information
Adobe addressed CVE-2025-21124 in the security update described in Adobe Security Bulletin APSB25-01. Update InDesign 2025 to the version listed as fixed in the bulletin, and update the InDesign 2024 branch beyond 19.5.1. Deploy through Adobe Creative Cloud Desktop or enterprise deployment tooling.
Workarounds
- Restrict opening of InDesign documents to files originating from trusted internal repositories.
- Use application allowlisting to prevent execution of unpatched InDesign binaries on managed endpoints.
- Isolate design workstations from sensitive network segments to limit the value of any leaked memory contents.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
