Highlights
Auth Bypass: 9 prior fixes. Scrutinize any change in this area.
lib/signers/v4.js: most-fixed (5 issues). Treat as high-risk during review.
2 high-severity fixes in this history; regressions here are high-impact.
Recurring patterns
The bug types that recur here, drawn from past fixes, not open vulnerabilities.
Auth Bypass: Signature Version 4 signing is highly sensitive to cache key collisions. Insufficient isolation of the cryptographic signature cache across changing Access Key IDs or different service clients can lead to signature reuse across distinct authentication boundaries.
Auth Bypass: Cognito Identity credentials can suffer from state pollution or leak stale identities if clearCachedId() routines fail to reset instance properties (such as identityId), or if identities are stored globally instead of being strictly partitioned by identity pool.
Information Disclosure: Invoking deprecated, uninitialized buffer constructors (e.g., via Base64 encoding helpers or event-streams) can expose raw system memory when numerical types are unexpectedly supplied as sizes rather than typed values.