CVE-2022-3213: ImageMagick Buffer Overflow Vulnerability

CVE-2022-3213 Overview

A heap buffer overflow vulnerability was discovered in ImageMagick's TIFF file processing functionality. When an application processes a specially crafted malformed TIFF file, the vulnerability can lead to undefined behavior or cause the application to crash, resulting in a denial of service condition. This vulnerability affects the image processing pipeline in ImageMagick, a widely-used software suite for manipulating and converting images across various formats.

Critical Impact

Processing a malicious TIFF file can trigger a heap buffer overflow, causing application crashes and denial of service. Organizations using ImageMagick for automated image processing are at risk of service disruption.

Affected Products

• ImageMagick (multiple versions)
• Fedora Project Extra Packages for Enterprise Linux 8.0 and 9.0
• Fedora Linux 35, 36, and 37

Discovery Timeline

• 2022-09-19 - CVE-2022-3213 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-3213

Vulnerability Analysis

This vulnerability is classified as a heap buffer overflow (CWE-787: Out-of-bounds Write) and improper restriction of operations within the bounds of a memory buffer (CWE-119). The flaw exists in ImageMagick's TIFF image decoder, specifically in the coders/tiff.c file where stripped TIFF images are processed. The vulnerability requires local access and user interaction to exploit, as a user must open or process a malicious TIFF file.

The core issue stems from an incorrect buffer size calculation when allocating memory for TIFF strip processing. The original code failed to account for the image's bit depth when calculating the extent of memory required for pixel data, leading to insufficient buffer allocation.

Root Cause

The root cause is an improper calculation of the buffer size (extent) used to store pixel data during TIFF strip conversion. The original calculation extent=4*(samples_per_pixel+1)*TIFFStripSize(tiff) did not factor in the image's bit depth (image->depth). When processing TIFF files with certain depth values, this resulted in an undersized buffer allocation. Subsequent write operations to this buffer would exceed its allocated bounds, causing a heap buffer overflow.

Attack Vector

The attack vector is local, requiring an attacker to deliver a maliciously crafted TIFF file to a victim's system. The victim must then process this file using ImageMagick, either directly via command-line tools like convert or identify, or indirectly through applications that leverage ImageMagick libraries for image processing. Successful exploitation leads to denial of service through application crashes.

The security patch corrects the buffer size calculation by including the image depth factor:

         /*
           Convert stripped TIFF image.
         */
-        extent=4*(samples_per_pixel+1)*TIFFStripSize(tiff);
+        extent=4*((image->depth+7)/8)*(samples_per_pixel+1)*TIFFStripSize(tiff);
         strip_pixels=(unsigned char *) AcquireQuantumMemory(extent,
           sizeof(*strip_pixels));
         if (strip_pixels == (unsigned char *) NULL)

Source: ImageMagick Commit Update

Detection Methods for CVE-2022-3213

Indicators of Compromise

• Application crashes when processing TIFF files, particularly in ImageMagick utilities or dependent applications
• Unexpected segmentation faults or memory access violations in image processing workflows
• Log entries indicating heap corruption or buffer overflow in processes using ImageMagick libraries

Detection Strategies

• Monitor for unusual crashes in ImageMagick processes (convert, mogrify, identify) when handling TIFF files
• Implement file integrity monitoring on ImageMagick library files to detect unauthorized modifications
• Deploy memory protection tools (AddressSanitizer, Valgrind) in development environments to detect heap overflows during testing

Monitoring Recommendations

• Enable crash reporting and logging for applications that process user-supplied images
• Monitor system logs for repeated crashes in image processing services that may indicate exploitation attempts
• Implement input validation to detect and quarantine malformed TIFF files before processing

How to Mitigate CVE-2022-3213

Immediate Actions Required

• Update ImageMagick to the latest patched version immediately
• Review and audit any automated image processing pipelines that accept user-supplied TIFF files
• Consider implementing file type validation and sandboxing for image processing operations
• Restrict ImageMagick policies to limit TIFF processing if not required

Patch Information

Security patches have been released by the ImageMagick project. The fix modifies the buffer allocation calculation in coders/tiff.c to properly account for image bit depth. Patches are available for both ImageMagick 7.x and ImageMagick 6.x branches:

• ImageMagick 7.x Patch
• ImageMagick 6.x Patch

For Fedora and EPEL users, updated packages should be available through standard package management channels. Consult the Red Hat Bug Report #2126824 for distribution-specific guidance.

Workarounds

• Disable TIFF processing in ImageMagick's policy.xml if TIFF support is not required
• Implement strict input validation to reject suspicious or malformed TIFF files before processing
• Run ImageMagick in a sandboxed environment to limit the impact of crashes
• Use content delivery validation to scan uploaded images before processing

# Configuration example - Disable TIFF processing in ImageMagick policy.xml
# Add to /etc/ImageMagick-6/policy.xml or /etc/ImageMagick-7/policy.xml
<policy domain="coder" rights="none" pattern="TIFF" />