CVE-2025-1403: IBM Qiskit DOS Vulnerability

CVE-2025-1403 Overview

CVE-2025-1403 is an Insecure Deserialization vulnerability affecting IBM Qiskit SDK versions 0.45.0 through 1.2.4. The vulnerability allows a remote attacker to cause a denial of service by crafting a malicious QPY file containing a malformed symengine serialization stream. When processed, this malicious file triggers a segmentation fault within the symengine library, crashing the application.

Critical Impact

Remote attackers can crash Qiskit SDK applications without authentication by supplying specially crafted QPY files, potentially disrupting quantum computing workflows and research operations.

Affected Products

• IBM Qiskit SDK versions 0.45.0 through 1.2.4
• Applications utilizing Qiskit's QPY file parsing functionality
• Quantum computing workflows that accept external QPY files

Discovery Timeline

• 2025-02-21 - CVE-2025-1403 published to NVD
• 2025-09-30 - Last updated in NVD database

Technical Details for CVE-2025-1403

Vulnerability Analysis

This vulnerability stems from improper handling of serialized data within Qiskit's QPY file format. QPY (Qiskit Python Serialization) is a binary format used for serializing and deserializing quantum circuits in Qiskit. The vulnerability specifically occurs during the deserialization process when the symengine library attempts to parse a malformed serialization stream.

The attack exploits the trust placed in QPY file contents without adequate validation. When Qiskit loads a QPY file, it passes serialized symengine expressions to the symengine library for reconstruction. A carefully crafted malformed stream can cause the symengine library to access invalid memory locations, resulting in a segmentation fault that terminates the entire process.

This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data), as the core issue lies in processing untrusted serialized content without sufficient validation of the data stream's integrity and format compliance.

Root Cause

The root cause is insufficient validation of symengine serialization streams within QPY files before they are passed to the symengine library for deserialization. The QPY parser does not adequately verify the structural integrity or bounds of the serialized data, allowing malformed streams to reach the underlying symengine deserialization routines and trigger memory access violations.

Attack Vector

The attack is network-accessible and requires no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Crafting a malicious QPY file with a corrupted symengine serialization stream
2. Delivering this file to a target system running a vulnerable Qiskit version
3. Triggering the application to load or process the malicious QPY file
4. The segfault occurs during deserialization, causing immediate application crash

The vulnerability is particularly concerning in scenarios where Qiskit applications accept QPY files from untrusted sources, such as collaborative quantum computing platforms, file-sharing services, or API endpoints that process user-submitted quantum circuit files.

Detection Methods for CVE-2025-1403

Indicators of Compromise

• Unexpected application crashes with segmentation fault signals in Qiskit-based services
• Core dumps containing symengine library stack traces during QPY file processing
• Unusual QPY file uploads or processing requests from external sources
• Repeated service restarts or watchdog triggers in quantum computing workflows

Detection Strategies

• Monitor application logs for SIGSEGV signals occurring during QPY file operations
• Implement file integrity checking on QPY files before processing
• Deploy application-level monitoring to detect abnormal crash patterns in Qiskit services
• Review system logs for core dumps associated with symengine library functions

Monitoring Recommendations

• Enable crash reporting and alerting for Qiskit-based applications
• Implement rate limiting on endpoints that accept QPY file uploads
• Monitor for patterns of malformed file submissions that could indicate probing attempts
• Deploy SentinelOne Singularity to detect and alert on application crash patterns indicative of exploitation attempts

How to Mitigate CVE-2025-1403

Immediate Actions Required

• Upgrade Qiskit SDK to version 1.2.5 or later immediately
• Audit all applications and workflows that process QPY files from external sources
• Implement input validation to reject suspiciously formatted QPY files before processing
• Consider isolating QPY file processing in sandboxed environments to limit crash impact

Patch Information

IBM has released a security patch addressing this vulnerability. Organizations should upgrade to Qiskit SDK version 1.2.5 or later, which includes fixes for the malformed symengine serialization handling. Detailed patch information and upgrade instructions are available in the IBM Support Advisory.

Workarounds

• Restrict QPY file uploads to trusted sources only until patching is complete
• Implement file scanning and validation checks before passing QPY files to Qiskit
• Run Qiskit applications in isolated containers with automatic restart capabilities to limit DoS impact
• Consider temporarily disabling QPY file import functionality for untrusted inputs if business requirements permit

# Upgrade Qiskit to patched version
pip install --upgrade qiskit>=1.2.5

# Verify installed version
python -c "import qiskit; print(qiskit.__version__)"