CVE-2025-21158 Overview
CVE-2025-21158 is an integer underflow vulnerability in Adobe InDesign Desktop affecting versions ID20.0, ID19.5.1, and earlier releases. The flaw maps to [CWE-191] (Integer Underflow - Wrap or Wraparound) and can lead to arbitrary code execution within the context of the current user. Exploitation requires user interaction: a victim must open a malicious InDesign file. Adobe published the corresponding fix in security bulletin APSB25-01 on the February 2025 Patch Tuesday.
Critical Impact
Successful exploitation grants attackers arbitrary code execution with the privileges of the user running InDesign, enabling malware installation, data theft, and lateral movement from a single crafted document.
Affected Products
- Adobe InDesign Desktop ID20.0
- Adobe InDesign Desktop ID19.5.1 and earlier
- Apple macOS and Microsoft Windows installations of the affected InDesign versions
Discovery Timeline
- 2025-02-11 - CVE-2025-21158 published to NVD alongside Adobe bulletin APSB25-01
- 2025-03-03 - Last updated in NVD database
Technical Details for CVE-2025-21158
Vulnerability Analysis
The vulnerability stems from improper handling of arithmetic operations on unsigned integer values within InDesign's file parsing logic. When parsing crafted structures inside an InDesign document, a subtraction operation produces a value below zero. The unsigned type wraps around to a large positive number, breaking subsequent length and bounds checks.
Downstream code then uses the corrupted value as a size or offset for memory operations. This corrupts heap state and allocates undersized buffers that subsequent operations overflow. Attackers shape the resulting memory layout to redirect control flow and execute arbitrary code in the user's session.
Root Cause
The defect is an integer underflow classified under [CWE-191]. InDesign performs an arithmetic operation on attacker-controlled length or count fields parsed from a document without first validating that operands fall within expected ranges. The wrapped result feeds memory allocation and copy routines, producing exploitable corruption.
Attack Vector
The attack vector is local and requires user interaction. An attacker crafts a malicious .indd or related InDesign file and delivers it through phishing email, file-sharing services, or compromised websites. Opening the file in a vulnerable version of InDesign triggers the underflow during parsing. No elevated privileges are required, and exploitation yields code execution at the privilege level of the InDesign process.
No public proof-of-concept exploit and no in-the-wild exploitation have been reported. The EPSS probability is 0.077% (percentile 23.159), reflecting low predicted exploitation likelihood.
See the Adobe InDesign Security Advisory APSB25-01 for vendor technical details.
Detection Methods for CVE-2025-21158
Indicators of Compromise
- Unexpected child processes spawned by InDesign.exe on Windows or Adobe InDesign 2024/2025 on macOS, particularly shells, scripting interpreters, or rundll32.exe.
- InDesign process performing outbound network connections to untrusted hosts shortly after opening a document.
- Crashes or anomalous memory exceptions logged by InDesign when opening externally sourced .indd, .indt, or .idml files.
Detection Strategies
- Monitor endpoint telemetry for InDesign processes launching command interpreters (cmd.exe, powershell.exe, bash, osascript) or writing executables to user-writable paths.
- Inspect email and web gateways for InDesign file types originating from external or unverified senders and detonate suspicious samples in a sandbox.
- Correlate InDesign process crashes with subsequent file-write or persistence activity in the same user session.
Monitoring Recommendations
- Inventory endpoints running Adobe InDesign and flag any still on ID20.0, ID19.5.1, or earlier builds.
- Enable application crash reporting and forward Windows Application event logs and macOS unified logs to a central SIEM.
- Track document-borne execution patterns from creative applications as part of phishing-response playbooks.
How to Mitigate CVE-2025-21158
Immediate Actions Required
- Update Adobe InDesign to the fixed versions listed in APSB25-01 on all Windows and macOS endpoints.
- Restrict opening of InDesign files received from external or untrusted sources until patching is complete.
- Run InDesign under standard user accounts rather than administrative accounts to limit blast radius if exploited.
Patch Information
Adobe addressed CVE-2025-21158 in the February 2025 security update for InDesign Desktop. Administrators should apply the updates documented in the Adobe InDesign Security Advisory APSB25-01. Deploy through Adobe Creative Cloud Desktop or enterprise deployment tooling such as the Adobe Admin Console.
Workarounds
- Block delivery of InDesign file extensions (.indd, .indt, .idml) at the email gateway from untrusted senders until patches are deployed.
- Use application allowlisting to prevent InDesign from launching child processes such as scripting interpreters and shells.
- Educate users to verify document provenance before opening InDesign files received externally.
# Verify installed Adobe InDesign version on Windows
reg query "HKLM\SOFTWARE\Adobe\InDesign" /s | findstr /i "Version"
# Verify installed Adobe InDesign version on macOS
mdls -name kMDItemVersion "/Applications/Adobe InDesign 2024/Adobe InDesign 2024.app"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
