GHSA-8v5f-hp78-jgxq Signature Verification Bypass in jwt-simple
An attacker can bypass JWT signature verification by exploiting algorithm confusion, allowing unauthorized access to protected resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-8v5f-hp78-jgxq?
GHSA-8v5f-hp78-jgxq is a vulnerability in jwt-simple, published on 6 Jun 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Versions of jwt-simple prior to 0.5.3 are vulnerable to Signature Verification Bypass. If no algorithm is specified in the decode() function, the packages uses the algorithm in the JWT to decode tokens. This allows an attacker to create a HS256 (symmetric algorithm) JWT with the server's public key as secret, and the package will verify it as HS256 instead of RS256 (asymmetric algorithm).
Recommendation
Upgrade to version 0.5.3 or later.
Which versions are affected by GHSA-8v5f-hp78-jgxq?
2 open source packages ship an affected version, including jwt-simple.
| Package | Affected | Fixed in |
|---|---|---|
jwt-simple npm | All versions | 0.5.3 |
jwt-simple npm | All versions | 0.5.3 |
How do I fix GHSA-8v5f-hp78-jgxq?
Upgrade jwt-simple to 0.5.3 or later.
Is GHSA-8v5f-hp78-jgxq being exploited?
There is no known exploitation of GHSA-8v5f-hp78-jgxq in the wild and no public exploit code.