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Fencer Intel
high —

GHSA-8v5f-hp78-jgxq json

Signature Verification Bypass in jwt-simple

published 7y ago modified 6y ago

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

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.

Patch / fix

  • npm jwt-simple 0.5.3

Is GHSA-8v5f-hp78-jgxq in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Affected packages

ecosystem package affected fixed in
npm jwt-simple
<0.5.3
0.5.3

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.