Node-cookie-signature before 1.0.6 is affected by a timing attack due to the type of comparison used.

Affected: npm: cookie-signature

Affected versions of `cookie-signature` are vulnerable to timing attacks as a result of using a fail-early comparison instead of a constant-time comparison.

Timing attacks remove the exponential increase in entropy gained from increased secret length, by providing per-character feedback on the correctness of a guess via miniscule timing differences.

Under favorable network conditions, an attacker can exploit this to guess the secret in no more than `charset*length` guesses, instead of `charset^length` guesses required were the timing attack not present.

## Recommendation

Update to 1.0.4 or later.

Affected: Ubuntu:16.04:LTS: node-cookie-signature, Ubuntu:18.04:LTS: node-cookie-signature

Node-cookie-signature before 1.0.6 is affected by a timing attack due to the type of comparison used.