CVE-2025-9287

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

Amit Schendel
Amit Schendel
Senior Security Researcher

Jan 1, 2026·6 min read·35 visits

Executive Summary (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.

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

Fix Analysis (1)

Technical Appendix

CVSS Score
9.1/ 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS Probability
0.12%
Top 100% most exploited

Affected Systems

crypto-browserifycreate-hashcreate-hmacBrowser-based cryptocurrency walletsFrontend JWT verification libraries

Affected Versions Detail

Product
Affected Versions
Fixed Version
cipher-base
crypto-browserify ecosystem
<= 1.0.41.0.5
AttributeDetail
CWE IDCWE-20 (Improper Input Validation)
CVSS9.1 (Critical)
Attack VectorNetwork / Local (Context Dependent)
ImpactIntegrity Violation / State Manipulation
Root CauseType Confusion in Buffer Handling
Fix Version1.0.5
CWE-20
Improper Input Validation

The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program.

Vulnerability Timeline

Vulnerability identified in input validation logic.
2025-01-10
Patch proposed in Pull Request #23.
2025-01-15
cipher-base v1.0.5 released.
2025-01-20

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