CVE-2025-54883: Vision UI Cryptographic Weakness Vulnerability

CVE-2025-54883 Overview

CVE-2025-54883 is a critical insecure random number generation vulnerability affecting Vision UI, a collection of enterprise-grade, dependency-free modules for modern web projects. The vulnerability exists in the getSecureRandomInt function within the security-kit component (versions prior to 3.5.0, packaged in Vision-UI versions 1.4.0 and below). Due to a silent 32-bit integer overflow in its internal masking logic, the function fails to produce a uniform distribution of random numbers when the requested range between min and max exceeds 2³² (4,294,967,296).

Critical Impact

Applications relying on this function for cryptographic operations, security tokens, or random value generation may be vulnerable to prediction attacks, significantly weakening the security posture of affected systems.

Affected Products

• Vision UI versions 1.4.0 and below
• Security-kit versions prior to 3.5.0
• Applications using getSecureRandomInt with ranges larger than 2³²

Discovery Timeline

• 2025-08-06 - CVE-2025-54883 published to NVD
• 2025-08-06 - Last updated in NVD database

Technical Details for CVE-2025-54883

Vulnerability Analysis

This vulnerability stems from a fundamental flaw in the cryptographic random number generation implementation within Vision UI's security-kit module. The getSecureRandomInt function is designed to produce cryptographically secure random integers within a specified range using rejection sampling—a standard technique for ensuring uniform distribution. However, the implementation contains a critical integer overflow bug that compromises the security guarantees when generating random numbers across large ranges.

When applications request random integers where the range (max - min) exceeds 2³², the function's masking algorithm produces biased outputs rather than uniformly distributed values. This bias can be exploited by attackers to predict generated values with higher probability than expected, undermining security mechanisms that depend on cryptographic randomness.

Root Cause

The root cause is the use of a 32-bit bitwise left-shift operation (<<) to generate a bitmask for the rejection sampling algorithm. In JavaScript and similar languages, bitwise operations treat operands as 32-bit signed integers. When the rejection sampling algorithm attempts to create a mask for ranges requiring 32 or more bits of entropy, the left-shift operation silently overflows, wrapping around and producing an incorrect (too small) mask value.

This incorrect mask causes the rejection sampling loop to accept values that should be rejected, resulting in a non-uniform distribution. The overflow is silent—no error is thrown—making it particularly dangerous as applications continue to function normally while producing cryptographically weak random numbers.

Attack Vector

The vulnerability is exploitable over the network without authentication or user interaction. An attacker targeting applications using the vulnerable getSecureRandomInt function can:

1. Identify applications using Vision UI's security-kit for random value generation
2. Analyze the predictable bias in generated values when large ranges are requested
3. Exploit the reduced entropy to predict security tokens, session identifiers, or cryptographic keys
4. Leverage predicted values to bypass authentication, forge tokens, or decrypt protected communications

The attack requires the target application to use getSecureRandomInt with a range exceeding 2³², which may occur in scenarios involving large identifier spaces, cryptographic key generation, or custom token schemes.

The vulnerability manifests when the bitwise left-shift operation overflows during mask generation. The shift operation is used to create a bitmask that should cover all bits required to represent the maximum possible value in the requested range. When the range exceeds 32 bits, the mask becomes incorrect, causing the rejection sampling algorithm to malfunction. See the GitHub Security Advisory for detailed technical information.

Detection Methods for CVE-2025-54883

Indicators of Compromise

• Applications generating predictable random values where cryptographic randomness was expected
• Security tokens or session identifiers showing statistical bias or patterns
• Anomalous authentication success rates suggesting token prediction attacks
• Audit logs showing successful use of tokens that should have been cryptographically unpredictable

Detection Strategies

• Perform dependency analysis to identify Vision UI versions 1.4.0 and below or security-kit versions prior to 3.5.0 in your codebase
• Conduct static code analysis to locate calls to getSecureRandomInt with large range parameters
• Review application logic to identify use cases where the range between min and max exceeds 2³²
• Implement statistical testing on generated random values to detect non-uniform distributions

Monitoring Recommendations

• Monitor for unusual patterns in security token generation or authentication flows
• Implement logging for random number generation in security-critical paths
• Alert on statistical anomalies in generated identifier sequences
• Track and correlate authentication bypass attempts that may indicate token prediction

How to Mitigate CVE-2025-54883

Immediate Actions Required

• Upgrade Vision UI to version 1.5.0 or later immediately
• Audit all code paths using getSecureRandomInt to identify potentially affected functionality
• Regenerate any cryptographic keys, tokens, or secrets generated using the vulnerable function
• Review security logs for signs of exploitation, including token reuse or prediction attacks

Patch Information

The vulnerability has been fixed in Vision UI version 1.5.0. The fix addresses the 32-bit integer overflow in the bitmask generation logic, ensuring proper handling of ranges requiring 32 or more bits of entropy. The patch commit is available at the GitHub Commit Reference.

Organizations should prioritize upgrading to the patched version. The GitHub Security Advisory provides additional context and upgrade guidance.

Workarounds

• Limit the range parameter in getSecureRandomInt calls to values smaller than 2³² until patching is complete
• Implement an alternative cryptographically secure random number generator for large-range requirements
• Use platform-native crypto APIs (e.g., crypto.getRandomValues()) directly for security-critical randomness
• Add runtime validation to reject getSecureRandomInt calls with ranges exceeding 2³²

# Update Vision UI to patched version
npm update vision-ui@1.5.0

# Verify installed version
npm list vision-ui

# Or update package.json manually and reinstall
# "vision-ui": "^1.5.0"
npm install