mcp-server-semgrep/semgrep-rules/scala/lang/security/audit/scalajs-eval.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: scalajs-eval
  mode: taint
  pattern-sources:
  - patterns:
    - pattern: $PARAM
    - pattern-either:
      - pattern-inside: |
          def $CTRL(..., $PARAM: $TYPE, ...) = {
            ...
          }
      - pattern-inside: |
          def $CTRL(..., $PARAM: $TYPE, ...) = $A {
            ...
          }
      - pattern-inside: |
          def $CTRL(..., $PARAM: $TYPE, ...) = $A(...) {
            ...
          }
  pattern-sinks:
  - patterns:
    - pattern: $JS.eval(...)
    - pattern-inside: |
        import scala.scalajs.$X
        ...
  message: >-
    `eval()` function evaluates JavaScript code represented as a string. Executing JavaScript from a string
    is an enormous security risk.
    It is far too easy for a bad actor to run arbitrary code when you use `eval()`.
    Do not use eval(). Alternatively: Ensure evaluated content is not definable by external sources.
    If it’s not possible, strip everything except alphanumeric characters from an input provided for the
    command string and arguments.
  metadata:
    references:
    - https://www.scala-js.org/doc/
    cwe:
    - "CWE-94: Improper Control of Generation of Code ('Code Injection')"
    owasp:
    - A03:2021 - Injection
    category: security
    technology:
    - scala
    - scala-js
    confidence: LOW
    cwe2022-top25: true
    subcategory:
    - vuln
    likelihood: LOW
    impact: HIGH
  languages: [scala]
  severity: WARNING