CVE-2025-9287: Broken Base: How `cipher-base` Rewound the Crypto Stack

Broken Base: How cipher-base Rewound the Crypto Stack

Vulnerability ID: CVE-2025-9287
CVSS Score: 9.1
Published: 2025-08-20

A critical flaw in the foundational cipher-base package allows attackers to manipulate cryptographic states and bypass integrity checks in browser-based applications.

TL;DR

The cipher-base package, a dependency of widely used libraries like crypto-browserify, failed to correctly handle TypedArray inputs. This improper validation allows attackers to pass malicious data structures that "rewind" or corrupt the internal hash state, leading to potential signature forgeries and collision attacks in browser environments.

---

⚠️ Exploit Status: POC

Technical Details

• CWE ID: CWE-20 (Improper Input Validation)
• CVSS: 9.1 (Critical)
• Attack Vector: Network / Local (Context Dependent)
• Impact: Integrity Violation / State Manipulation
• Root Cause: Type Confusion in Buffer Handling
• Fix Version: 1.0.5

Affected Systems

• crypto-browserify
• create-hash
• create-hmac
• Browser-based cryptocurrency wallets
• Frontend JWT verification libraries
• cipher-base: <= 1.0.4 (Fixed in: 1.0.5)

Code Analysis

Commit: 4f56f1f

Fix buffer handling for TypedArrays and DataViews

+ if (useArrayBuffer && ArrayBuffer.isView(data)) {
+   bufferData = Buffer.from(data.buffer, data.byteOffset, data.byteLength)
+ }

Exploit Details

• GitHub: Discussion regarding TypedArray handling issues leading to state corruption.

Mitigation Strategies

• Dependency Audit
• Force Resolution
• Input Sanitization

Remediation Steps:

1. Run npm audit to identify the vulnerable dependency chain.
2. Update cipher-base to version 1.0.5 or higher.
3. If cipher-base is a nested dependency (it usually is), use npm update or manually force the resolution in package.json using the overrides (npm) or resolutions (yarn) field.
4. Re-build your frontend bundles. The fix must be present in the bundled JavaScript served to the client.

References

• PR #23: Fix TypedArray handling
• crypto-browserify Repository

---

Read the full report for CVE-2025-9287 on our website for more details including interactive diagrams and full exploit analysis.