Security readout for executives and security teams
Plain-English summary
CVE-2018-20579 affects Contiki-NG versions before 4.2. A JSON parsing bug can write past a stack buffer when handling nested object or array characters. Business urgency depends on whether affected Contiki-NG code is present in deployed embedded or IoT firmware and whether it parses untrusted JSON.
Executive priority
Treat as an exposure-discovery item for embedded assets rather than an immediate confirmed crisis. Prioritize environments with externally reachable JSON inputs or difficult-to-update firmware, because the vulnerability is memory corruption and the public record lacks severity detail.
Technical view
The CVE describes a stack-based buffer overflow in the push function of os/lib/json/jsonparse.c. The out-of-bounds write is limited in the description to a '{' or '[' character. The public record does not provide CVSS, CWE, exploitability, impact scope, or detailed remediation guidance beyond the before-4.2 affected range.
Likely exposure
Likely exposure is embedded or IoT software built with Contiki-NG before 4.2 that includes the JSON parser and processes attacker-controlled or externally supplied JSON. The source bundle does not identify specific downstream devices, vendors, CPEs, or deployment environments.
Exploitation context
The source bundle does not report active exploitation, public exploit use, or KEV listing. It identifies a memory corruption condition but does not establish whether it causes denial of service, code execution, or another security impact in real deployments.
Researcher notes
Key gaps are CVSS, CWE mapping, exploitability, impact outcome, and downstream affected products. Analysis should stay close to Contiki-NG before 4.2 and the jsonparse.c push function unless additional vendor-specific evidence is found.
Mitigation direction
- Inventory firmware and products using Contiki-NG before 4.2.
- Check Contiki-NG vendor guidance and issue 601 for the fixed code path.
- Plan upgrade or backport to a non-affected Contiki-NG version where feasible.
- Reduce exposure of components parsing untrusted JSON until remediated.
Validation and detection
- Confirm whether os/lib/json/jsonparse.c is present in firmware builds.
- Identify deployed Contiki-NG versions and compare against the before-4.2 affected range.
- Review code paths that feed external JSON into the parser.
- Track remediation evidence through firmware SBOMs or source control history.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2018-20579 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
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/contiki-ng/contiki-ng/issues/601CVE reference · x_refsource_MISC
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.