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CVE Record

CVE-2018-11627: Sinatra before 2.0.2 has XSS via the 400 Bad Request page that occurs upon a params parser exception.

Sinatra before 2.0.2 has XSS via the 400 Bad Request page that occurs upon a params parser exception.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Sinatra versions before 2.0.2 could expose users to cross-site scripting on the default 400 Bad Request page when parameter parsing fails. For affected web applications, the business risk is browser-side compromise of users interacting with a vulnerable app. The source bundle provides no CVSS score and no evidence of active exploitation.

Executive priority

Treat as a targeted remediation item, especially for public Sinatra applications. It is not KEV-listed in the provided bundle, but XSS in a web framework can affect user trust and session security if vulnerable apps remain exposed.

Technical view

CVE-2018-11627 is an XSS issue in Sinatra before 2.0.2, triggered when a params parser exception is rendered through the 400 Bad Request response. Public references include a Sinatra issue, a fixing commit, and Red Hat advisories. The bundle does not provide CWE, CVSS, or complete downstream package mapping.

Likely exposure

Exposure is most likely in internet-facing Ruby web applications using Sinatra before 2.0.2, including downstream packaged deployments referenced by Red Hat advisories. The bundle does not identify specific vulnerable applications or distributions beyond those references.

Exploitation context

The bundle does not show KEV listing or active exploitation evidence. The described condition requires reaching an affected Sinatra application and causing a parameter parser exception that leads to unsafe 400 error-page rendering.

Researcher notes

Evidence is sparse: the source bundle gives the core affected range and trigger, but no CVSS, CWE, exploit status, or complete package matrix. Use the Sinatra issue and commit to understand the fix behavior without deriving exploit procedures.

Mitigation direction

  • Upgrade Sinatra to 2.0.2 or later where feasible.
  • Review Red Hat advisories for supported package updates.
  • Check vendor guidance for downstream packages and backports.
  • Avoid exposing verbose framework error output in production.
  • Prioritize externally reachable Sinatra applications first.

Validation and detection

  • Inventory applications using Sinatra and record installed versions.
  • Confirm whether any instance runs Sinatra before 2.0.2.
  • Check OS vendor packages against Red Hat advisory versions where applicable.
  • Review production error handling for 400 Bad Request responses.
  • Confirm fixes through dependency manifests and deployed artifact inspection.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2018-11627 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.