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CVE-2023-48238

Joaquimserafim Json Web Token vulnerability

7.5 HIGHPublic exploitEPSS 0.31%
  1. Published17 Nov 2023

Description

joaquimserafim/json-web-token is a javascript library use to interact with JSON Web Tokens (JWT) which are a compact URL-safe means of representing claims to be transferred between two parties. Versions prior to 4.0.0 are vulnerable to a JWT algorithm confusion attack. On line 86 of the 'index.js' file, the algorithm to use for verifying the signature of the JWT token is taken from the JWT token, which at that point is still unverified and thus shouldn't be trusted. To exploit this vulnerability, an attacker needs to craft a malicious JWT token containing the HS256 algorithm, signed with the public RSA key of the victim application. This attack will only work against this library is the RS256 algorithm is in use, however it is a best practice to use that algorithm. Version 4.0.0 fixes the issue.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

Joaquimserafim Json Web Token< 3.1.1

Remediation

Fixed in
Joaquimserafim Json Web Token≥ 3.1.1

References

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Frequently asked

Is CVE-2023-48238 being actively exploited?

CVE-2023-48238 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.31%.

How severe is CVE-2023-48238?

CVE-2023-48238 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 0.31% probability of exploitation.

Which products are affected by CVE-2023-48238?

Affected products include Joaquimserafim Json Web Token.

How do I fix CVE-2023-48238?

Upgrade affected software to a fixed version, for example Joaquimserafim Json Web Token 3.1.1 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2023-48238 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.