CVE-2025-53019: ImageMagick Memory Leak DoS Vulnerability

CVE-2025-53019 Overview

ImageMagick, the widely-used open-source software for editing and manipulating digital images, contains a memory leak vulnerability in versions prior to 7.1.2-0 and 6.9.13-26. The vulnerability exists in ImageMagick's magick stream command, where specifying multiple consecutive %d format specifiers in a filename template causes a memory leak. This flaw can be exploited remotely without authentication to cause denial of service through resource exhaustion.

Critical Impact

Remote attackers can trigger memory exhaustion by exploiting the filename template parsing in the magick stream command, potentially leading to service disruption and system instability on affected servers.

Affected Products

• ImageMagick versions prior to 7.1.2-0
• ImageMagick versions prior to 6.9.13-26
• Systems running vulnerable ImageMagick packages (including Debian distributions)

Discovery Timeline

• 2025-07-14 - CVE-2025-53019 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-53019

Vulnerability Analysis

This vulnerability is classified under CWE-401 (Missing Release of Memory after Effective Lifetime) and CWE-125 (Out-of-Bounds Read). The flaw resides in how ImageMagick's magick stream command processes filename templates containing format specifiers. When a user provides a filename template with multiple consecutive %d format specifiers, the application fails to properly release allocated memory, resulting in a memory leak condition.

The vulnerability can be exploited remotely over the network without requiring any user interaction or special privileges. An attacker can craft malicious input that triggers repeated memory allocations without corresponding deallocations, eventually exhausting available system memory and causing denial of service.

Root Cause

The root cause lies in improper memory management within the filename template parsing logic of the magick stream command. When processing multiple consecutive %d format specifiers, the code allocates memory buffers for each specifier but fails to implement proper cleanup mechanisms. This missing release of memory after effective lifetime allows memory consumption to grow unbounded during processing operations.

Attack Vector

The attack can be executed remotely over the network. An attacker can exploit this vulnerability by sending specially crafted input to applications or services that process images using vulnerable ImageMagick versions. The attack requires no authentication or user interaction, making it particularly dangerous for web applications and automated image processing pipelines.

The exploitation involves providing a filename template with multiple consecutive %d format specifiers to the magick stream command. Each invocation leaks memory, and repeated exploitation can lead to memory exhaustion on the target system. This primarily impacts availability by causing denial of service conditions.

Detection Methods for CVE-2025-53019

Indicators of Compromise

• Unusual memory consumption patterns on systems running ImageMagick
• Unexpected growth in memory usage during image processing operations
• System performance degradation or out-of-memory errors related to ImageMagick processes
• Presence of filename patterns with multiple consecutive %d specifiers in logs

Detection Strategies

• Monitor memory usage trends for ImageMagick-related processes using system monitoring tools
• Implement logging and alerting for abnormal resource consumption patterns
• Review application logs for suspicious filename template patterns containing multiple %d specifiers
• Deploy file integrity monitoring on ImageMagick binaries to detect version changes

Monitoring Recommendations

• Configure memory usage thresholds and alerts for image processing services
• Implement process monitoring to detect runaway ImageMagick instances
• Review system logs for OOM (Out of Memory) killer events related to ImageMagick
• Monitor for unexpected termination of image processing services

How to Mitigate CVE-2025-53019

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
• Review and update Debian systems using the patches referenced in the Debian LTS Announcement
• Audit applications that utilize ImageMagick's magick stream command

Patch Information

ImageMagick has released fixed versions that address this memory leak vulnerability. Version 7.1.2-0 fixes the issue for the 7.x branch, while version 6.9.13-26 provides the fix for the 6.x branch. Full details are available in the GitHub Security Advisory. Debian users should apply updates referenced in the Debian LTS Announcement.

Workarounds

• Restrict access to the magick stream command by limiting which users or processes can invoke it
• Implement input validation to sanitize filename templates before passing them to ImageMagick
• Configure resource limits (memory, CPU) for ImageMagick processes using cgroups or similar mechanisms
• Consider isolating ImageMagick processing in containers with strict resource constraints

# Configuration example - Limit ImageMagick memory usage via policy.xml
# Edit /etc/ImageMagick-7/policy.xml or /etc/ImageMagick-6/policy.xml
# Add or modify the following resource limits:
<policy domain="resource" name="memory" value="256MiB"/>
<policy domain="resource" name="map" value="512MiB"/>
<policy domain="resource" name="disk" value="1GiB"/>