CVE-2025-53014: ImageMagick Buffer Overflow Vulnerability

CVE-2025-53014 Overview

CVE-2025-53014 is a heap buffer overflow vulnerability in ImageMagick, the widely-used open-source software for editing and manipulating digital images. The vulnerability exists in the InterpretImageFilename function and stems from an off-by-one error that causes out-of-bounds memory access when processing format strings containing consecutive percent signs (%%).

ImageMagick is deployed extensively across web applications, content management systems, and image processing pipelines, making this vulnerability particularly concerning for organizations that rely on automated image processing workflows. The flaw affects versions prior to 7.1.2-0 and 6.9.13-26.

Critical Impact

Remote attackers can exploit this heap buffer overflow to potentially achieve arbitrary code execution, compromise system integrity, or cause denial of service through memory corruption.

Affected Products

• ImageMagick versions prior to 7.1.2-0
• ImageMagick versions prior to 6.9.13-26
• Systems and applications using vulnerable ImageMagick libraries for image processing

Discovery Timeline

• 2025-07-14 - CVE-2025-53014 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-53014

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), though it manifests as a heap buffer overflow condition. The root cause is an off-by-one error in the InterpretImageFilename function, which handles the parsing and interpretation of filename format strings.

When ImageMagick processes format strings that contain consecutive percent signs (%%), the function miscalculates buffer boundaries, leading to out-of-bounds memory access. This type of vulnerability can be exploited remotely since ImageMagick is commonly used in web applications to process user-uploaded images or dynamically generate image content based on user-controlled input.

The vulnerability is exploitable over the network without requiring authentication or user interaction, and successful exploitation can result in complete compromise of the affected system's confidentiality, integrity, and availability.

Root Cause

The vulnerability originates from an off-by-one error in the InterpretImageFilename function within ImageMagick's core image processing code. When parsing format strings, the function fails to correctly account for buffer size when encountering consecutive percent sign characters (%%). This boundary calculation error allows memory operations to exceed allocated buffer limits, resulting in heap buffer overflow conditions.

Off-by-one errors are particularly insidious because they often pass initial testing but can be exploited to corrupt adjacent memory structures, overwrite function pointers, or leak sensitive information from process memory.

Attack Vector

Attackers can exploit this vulnerability by crafting malicious image files or format strings that include consecutive percent signs. When ImageMagick processes these specially crafted inputs through the InterpretImageFilename function, the off-by-one error triggers out-of-bounds memory access.

Attack scenarios include:

1. Web Application Exploitation: Uploading a malicious image to a web application that uses ImageMagick for image processing
2. Command Injection via Filename: Providing crafted filename patterns to ImageMagick command-line tools
3. API Abuse: Sending malformed requests to services that expose ImageMagick functionality through APIs

The vulnerability is exploitable through network-based vectors, requires no privileges or authentication, and does not depend on user interaction, making it highly dangerous in exposed environments.

Detection Methods for CVE-2025-53014

Indicators of Compromise

• Unusual crashes or segmentation faults in ImageMagick processes or applications using ImageMagick libraries
• Unexpected memory consumption spikes in image processing services
• Application logs showing errors related to InterpretImageFilename function or format string parsing
• Core dumps or crash reports indicating heap corruption in ImageMagick components

Detection Strategies

• Monitor for ImageMagick process crashes or abnormal terminations that may indicate exploitation attempts
• Implement input validation to detect and block filenames or format strings containing suspicious patterns of consecutive percent signs
• Deploy memory protection mechanisms like ASLR and heap canaries to detect buffer overflow attempts
• Use application-level firewalls to inspect and filter potentially malicious image upload requests

Monitoring Recommendations

• Enable detailed logging for ImageMagick operations and monitor for unusual format string patterns
• Implement runtime application self-protection (RASP) for web applications that process images with ImageMagick
• Set up alerts for abnormal process behavior in systems running ImageMagick, including unexpected memory access patterns
• Conduct regular vulnerability scanning to identify systems running vulnerable ImageMagick versions

How to Mitigate CVE-2025-53014

Immediate Actions Required

• Upgrade ImageMagick to version 7.1.2-0 or later for the 7.x branch
• Upgrade ImageMagick to version 6.9.13-26 or later for the 6.x branch
• Audit all systems, containers, and applications that include ImageMagick dependencies for vulnerable versions
• Implement strict input validation for any user-controlled data passed to ImageMagick functions

Patch Information

ImageMagick has released patched versions that address this heap buffer overflow vulnerability. The fix corrects the off-by-one error in the InterpretImageFilename function to properly handle consecutive percent signs in format strings.

For detailed patch information, refer to the ImageMagick GitHub Security Advisory. Debian users should also consult the Debian LTS Announcement for distribution-specific updates.

Workarounds

• Restrict ImageMagick's processing capabilities using policy.xml configuration to disable unnecessary coders and features
• Implement sandboxing for ImageMagick processes using containers, seccomp profiles, or similar isolation technologies
• Apply strict input sanitization to filter format strings before they reach ImageMagick functions
• Consider using alternative image processing libraries for untrusted input until patches can be applied

# Example policy.xml configuration to restrict ImageMagick capabilities
# Location: /etc/ImageMagick-6/policy.xml or /etc/ImageMagick-7/policy.xml

# Disable potentially dangerous coders
# <policy domain="coder" rights="none" pattern="EPHEMERAL" />
# <policy domain="coder" rights="none" pattern="URL" />
# <policy domain="coder" rights="none" pattern="HTTPS" />
# <policy domain="coder" rights="none" pattern="MVG" />
# <policy domain="coder" rights="none" pattern="MSL" />

# Limit resource usage to mitigate denial of service
# <policy domain="resource" name="memory" value="256MiB"/>
# <policy domain="resource" name="map" value="512MiB"/>
# <policy domain="resource" name="disk" value="1GiB"/>