CVE-2026-21489: iccDEV Buffer Overflow Vulnerability

CVE-2026-21489 Overview

iccDEV is a set of libraries and tools for working with ICC color management profiles. Versions 2.3.1.1 and below contain Out-of-bounds Read and Integer Underflow (Wrap or Wraparound) vulnerabilities in the CIccCalculatorFunc::SequenceNeedTempReset function. These memory corruption issues can be triggered when processing maliciously crafted ICC color profiles, potentially leading to information disclosure or application crashes.

Critical Impact

Local attackers can exploit integer underflow and out-of-bounds read vulnerabilities to cause denial of service conditions or potentially leak sensitive memory contents through specially crafted ICC profile files.

Affected Products

• iccDEV versions 2.3.1.1 and below
• Applications integrating the iccDEV library for ICC color profile processing
• Systems processing untrusted ICC color profile files

Discovery Timeline

• 2026-01-06 - CVE CVE-2026-21489 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2026-21489

Vulnerability Analysis

This vulnerability involves two related memory safety issues within the CIccCalculatorFunc::SequenceNeedTempReset function in the iccDEV library. The root cause stems from insufficient validation of arithmetic operations before performing memory access operations.

The integer underflow occurs when calculating array indices or sizes without properly validating that the subtraction operation won't wrap around to a large positive value. When combined with the out-of-bounds read (CWE-125), this allows an attacker to read memory outside the intended buffer boundaries.

Exploitation requires user interaction to process a maliciously crafted ICC color profile file. While the attack is local in nature, it could be triggered by opening documents or images containing embedded malicious color profiles in applications that use the vulnerable library.

Root Cause

The vulnerability exists in IccProfLib/IccMpeCalc.cpp where the code performs arithmetic operations on array indices without validating that the resulting values remain within expected bounds. Specifically, the subtraction operation nOps-p can result in an integer underflow when p exceeds nOps, causing the value to wrap around to a very large number.

Attack Vector

An attacker can craft a malicious ICC color profile containing specific calculator function sequences that trigger the vulnerable code path. When a victim opens or processes a file containing this malicious profile, the integer underflow occurs during the SequenceNeedTempReset recursive call, leading to out-of-bounds memory reads. This requires local access and user interaction to open the malicious file.

// Security patch demonstrating the fix
// Source: https://github.com/InternationalColorConsortium/iccDEV/commit/cfabfe52c9c7eb0481b62c8aad56580bb11efdad

       memcpy(ifTemps, tempUsage, nMaxTemp);
 
       p=i+2;
+      if (p > nOps)
+        return true;
       rv = rv || SequenceNeedTempReset(&op[p], icIntMin(nOps-p, op[i].data.size), ifTemps, nMaxTemp);
 
       if (i<nOps && op[i+1].sig==icSigElseOp) {

The patch adds a bounds check to verify that p does not exceed nOps before performing the subtraction, preventing the integer underflow condition.

Detection Methods for CVE-2026-21489

Indicators of Compromise

• Unexpected application crashes when opening files containing ICC color profiles
• Memory access violations or segmentation faults in processes using iccDEV library
• Anomalous file processing activity involving .icc or .icm color profile files
• Process dumps showing crashes within CIccCalculatorFunc::SequenceNeedTempReset or related functions

Detection Strategies

• Monitor for crash reports and exceptions originating from iccDEV library components
• Implement file integrity monitoring for applications that process ICC profiles
• Deploy endpoint detection rules to identify unusual memory access patterns in color profile processing
• Analyze application logs for repeated failures when processing specific ICC profile files

Monitoring Recommendations

• Enable enhanced logging for applications that process ICC color profiles
• Configure SentinelOne to monitor for out-of-bounds memory access patterns
• Implement behavioral analysis for file processing operations involving color profiles
• Set up alerts for application crashes with stack traces involving IccMpeCalc.cpp or related calculator functions

How to Mitigate CVE-2026-21489

Immediate Actions Required

• Upgrade iccDEV library to version 2.3.1.2 or later immediately
• Identify all applications in your environment that use the iccDEV library
• Restrict processing of ICC profiles from untrusted sources until patching is complete
• Enable application sandboxing where possible to limit the impact of potential exploitation

Patch Information

The vulnerability has been fixed in iccDEV version 2.3.1.2. The patch adds proper bounds checking to prevent integer underflow before the subtraction operation in the SequenceNeedTempReset function. Organizations should update to the patched version by referencing the GitHub Security Advisory and the commit implementing the fix.

Workarounds

• Implement input validation to reject ICC profiles from untrusted sources
• Run applications that process ICC profiles in sandboxed or isolated environments
• Disable ICC profile processing functionality if not required for business operations
• Use application whitelisting to restrict execution of potentially vulnerable applications

# Configuration example - Verify installed iccDEV version and update
# Check current version of iccDEV library
pkg-config --modversion iccDEV 2>/dev/null || echo "Version check failed"

# Update to patched version 2.3.1.2 or later
cd /path/to/iccDEV
git fetch origin
git checkout v2.3.1.2
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
sudo cmake --install build