Security readout for executives and security teams
Plain-English summary
CVE-2018-20578 is a denial-of-service flaw in NuttX before 7.27. A crafted HTTP redirect can make the web client loop indefinitely when parsing an oversized Location URL. Business urgency depends on whether affected NuttX networking code is used in devices that fetch attacker-controlled or untrusted URLs.
Executive priority
Treat as targeted remediation for affected embedded products, not a broad enterprise emergency. Prioritize internet-connected or safety-critical devices that use NuttX webclient networking and can receive redirects from untrusted sources.
Technical view
The issue is in netlib_parsehttpurl() in apps/netutils/netlib/netlib_parsehttpurl.c. URLs longer than the configured host buffer length are mishandled; the NuttX webclient default host length is 40 bytes. The documented vector is the Location header of an HTTP 3xx response, resulting in an infinite loop.
Likely exposure
Likely limited to embedded or RTOS deployments running NuttX before 7.27 and using the affected netutils webclient URL parsing path. Exposure is higher when devices follow HTTP redirects from untrusted networks or services.
Exploitation context
The source bundle does not show CISA KEV listing, public active exploitation, CVSS scoring, or proof-of-concept details. It does identify a remotely influenced redirect-header vector that can trigger denial of service.
Researcher notes
Evidence is narrow but specific: affected code path, version boundary, buffer-length condition, and redirect-header vector are stated. Missing data includes CVSS, CWE, exploit prevalence, and vendor-maintained mitigation detail beyond the NuttX 7.27 boundary.
Mitigation direction
- Identify NuttX versions in firmware, products, and vendor SDKs.
- Upgrade affected NuttX deployments to 7.27 or later where feasible.
- Check NuttX/vendor guidance for any maintained backport or workaround.
- Reduce use of untrusted HTTP redirects in affected device workflows.
Validation and detection
- Confirm whether the product uses NuttX before 7.27.
- Check whether netutils webclient and netlib_parsehttpurl() are compiled into firmware.
- Review HTTP client behavior for automatic 3xx redirect following.
- Verify remediation by confirming upgraded NuttX source or vendor firmware provenance.
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-2018-20578 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://bitbucket.org/nuttx/nuttx/issues/119/denial-of-service-infinite-loop-whileCVE reference · x_refsource_MISC
- https://bitbucket.org/nuttx/nuttx/downloads/nuttx-7_27-README.txtCVE 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.