Security readout for executives and security teams
Plain-English summary
This flaw affects Nov json-jwt when decrypting AES-GCM encrypted JSON Web Tokens. A vulnerable service may accept a forged authentication tag, undermining token integrity. The practical business risk is highest where json-jwt protects login, sessions, API access, or trusted service-to-service tokens.
Executive priority
Treat as high priority for any authentication-facing service using vulnerable json-jwt versions. If the library is absent or only used offline, urgency is lower. The patch path is clear: move to 1.9.4 or later, or the fixed distribution package.
Technical view
CVE-2018-1000539 is a CWE-347 improper cryptographic signature verification issue in json-jwt versions >= 0.5.0 and < 1.9.4. The issue concerns AES-GCM encrypted JWT decryption and may allow authentication tag forgery over a network-accessible path. Sources state it was fixed in 1.9.4 and later.
Likely exposure
Exposure is likely limited to systems that use Nov json-jwt versions >= 0.5.0 and < 1.9.4, especially where externally supplied encrypted JWTs are decrypted for authentication or authorization decisions.
Exploitation context
The source bundle says exploitation appears possible via network connectivity. It does not provide evidence of public exploitation, and this CVE is not listed as KEV in the provided data.
Researcher notes
The public bundle is sparse: no CVSS vector, no affected CPEs, and no exploit evidence. The strongest technical signal is the stated AES-GCM authentication tag forgery during encrypted JWT decryption, fixed by upstream PR and Debian advisory.
Mitigation direction
- Upgrade json-jwt to version 1.9.4 or later.
- Apply Debian DSA-4283 package updates where Debian packages are used.
- Prioritize services that decrypt externally supplied AES-GCM encrypted JWTs.
- Check vendor and distribution guidance for supported fixed versions.
- Rotate affected tokens if vulnerable token handling was exposed.
Validation and detection
- Inventory dependency manifests and lockfiles for json-jwt usage.
- Confirm deployed runtime versions are not >= 0.5.0 and < 1.9.4.
- Identify authentication paths that decrypt AES-GCM encrypted JWTs.
- Verify Debian hosts are patched according to DSA-4283.
- Review logs for suspicious token validation failures or anomalies.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2018-1000539 mapping review
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Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/nov/json-jwt/pull/62CVE reference · x_refsource_MISC
- DSA-4283CVE reference · vendor-advisory, x_refsource_DEBIAN
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.