CVE-2026-34533 Overview
A type confusion vulnerability exists in iccDEV, a library for working with ICC color management profiles. Prior to version 2.3.1.6, a crafted ICC profile can trigger Undefined Behavior (UB) in CIccCalculatorFunc::ApplySequence() due to invalid enum values being loaded for icChannelFuncSignature. This vulnerability allows attackers to cause a denial of service condition through specially crafted ICC profile files.
Critical Impact
Malicious ICC profiles can trigger undefined behavior leading to application crashes and denial of service in systems processing color management profiles.
Affected Products
- iccDEV versions prior to 2.3.1.6
- Applications and systems using vulnerable iccDEV libraries for ICC profile processing
- Color management workflows that process untrusted ICC profile data
Discovery Timeline
- 2026-03-31 - CVE-2026-34533 published to NVD
- 2026-04-01 - Last updated in NVD database
Technical Details for CVE-2026-34533
Vulnerability Analysis
This vulnerability stems from improper handling of enumeration values during ICC profile parsing. The CIccCalculatorFunc::ApplySequence() function processes channel function signatures from ICC profile data without adequate validation of the enum values. When a malformed ICC profile contains invalid icChannelFuncSignature values, the function loads these values directly, resulting in undefined behavior.
The issue was identified using UndefinedBehaviorSanitizer (UBSan), which flagged the condition as a "load of value … not a valid value for type icChannelFuncSignature". This indicates a type/enum value confusion scenario where the application assumes incoming data conforms to valid enumeration ranges but fails to verify this assumption before use.
The local attack vector requires an attacker to provide a malicious ICC profile to a victim system or application. This could occur through various delivery mechanisms including email attachments, file downloads, or content processed by image manipulation software.
Root Cause
The root cause is categorized as CWE-758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior). The vulnerability occurs because the code directly loads enumeration values from untrusted ICC profile data without bounds checking or validation against valid enum ranges. When invalid values are loaded into an enum type, the C/C++ standard defines this as undefined behavior, which can manifest as crashes, memory corruption, or unpredictable program states.
Attack Vector
An attacker can exploit this vulnerability by crafting a malicious ICC profile with invalid icChannelFuncSignature enum values embedded in the profile's calculator function sequence data. When a vulnerable application processes this profile, the invalid enum values trigger undefined behavior in CIccCalculatorFunc::ApplySequence(), potentially causing the application to crash.
The vulnerability manifests during ICC profile processing when channel function signatures are parsed and applied. Technical details regarding the specific invalid enum handling can be found in the GitHub Issue #664 and the GitHub Security Advisory GHSA-8jj3-77m7-c3pq.
Detection Methods for CVE-2026-34533
Indicators of Compromise
- Application crashes or unexpected terminations during ICC profile processing operations
- UBSan errors in logs indicating "load of value not a valid value for type icChannelFuncSignature"
- Suspicious ICC profile files with malformed calculator function sequence data
- Repeated denial of service conditions in color management workflows
Detection Strategies
- Monitor for application crashes associated with ICC profile processing functions
- Deploy UndefinedBehaviorSanitizer (UBSan) instrumented builds in test environments to detect enum value violations
- Implement file integrity monitoring for incoming ICC profile files
- Review system logs for segmentation faults or abnormal terminations in processes using iccDEV libraries
Monitoring Recommendations
- Enable crash reporting and analysis for applications utilizing iccDEV libraries
- Implement sandboxing for ICC profile processing to contain potential crashes
- Monitor file upload endpoints for suspicious ICC profile submissions
- Track version information of iccDEV libraries deployed across infrastructure
How to Mitigate CVE-2026-34533
Immediate Actions Required
- Upgrade iccDEV to version 2.3.1.6 or later immediately
- Restrict processing of ICC profiles from untrusted sources until patches are applied
- Implement input validation for ICC profile files before processing
- Consider sandboxing color management operations to limit impact of exploitation
Patch Information
The vulnerability has been patched in iccDEV version 2.3.1.6. The fix implements proper validation of enum values before loading them into icChannelFuncSignature types, preventing the undefined behavior condition. Details of the patch are available in GitHub Pull Request #681.
Organizations should update their iccDEV installations through their standard software update processes or by obtaining the latest release from the official repository.
Workarounds
- Validate ICC profiles against known-good templates before processing
- Implement application-level sandboxing for color management operations
- Restrict file permissions to prevent unauthorized ICC profile modifications
- Use containerization to isolate ICC profile processing workloads from critical systems
# Verify iccDEV version to confirm patch status
# Check if version is 2.3.1.6 or higher
iccDump -v 2>&1 | grep -i version
# Restrict permissions on ICC profile directories
chmod 750 /path/to/icc/profiles
chown root:colormanagement /path/to/icc/profiles
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
