codeql/change-notes/1.18/analysis-javascript.md

Improvements to JavaScript analysis

General improvements

• Additional heuristics have been added to semmle.javascript.heuristics. Add import semmle.javascript.heuristics.all to a query in order to activate all of the heuristics at once.

• Modelling of data flow through destructuring assignments has been improved. This may give additional results for the security queries and other queries that rely on data flow.

• Modelling of global variables has been improved. This may give more true-positive results and fewer false-positive results for a variety of queries.

• Modelling of re-export declarations has been improved. This may result in fewer false-positive results for a variety of queries.

• Modelling of taint flow through array operations has been improved. This may give additional results for the security queries.

• The taint tracking library recognizes more ways in which taint propagates. In particular, some flow through string formatters is now recognized. This may give additional results for the security queries.

• The taint tracking library now recognizes additional sanitization patterns. This may give fewer false-positive results for the security queries.

• Type inference for simple function calls has been improved. This may give additional results for queries that rely on type inference.

• Support for popular libraries has been improved. Consequently, queries may produce more results on code bases that use the following libraries:

  • bluebird
  • browserid-crypto
  • compose-function
  • cookie-parser
  • cookie-session
  • crypto-js
  • deep-assign
  • deep-extend
  • deep-merge
  • deep
  • deepmerge
  • defaults-deep
  • defaults
  • dottie
  • dotty
  • ent
  • entities
  • escape-goat
  • express-jwt
  • express-session
  • extend-shallow
  • extend
  • extend2
  • fast-json-parse
  • forge
  • format-util
  • global
  • he
  • html-entities
  • jquery
  • js-extend
  • json-parse-better-errors
  • json-parse-safe
  • json-safe-parse
  • just-compose
  • just-extend
  • lodash
  • merge-deep
  • merge-options
  • merge
  • mixin-deep
  • mixin-object
  • MySQL2
  • node.extend
  • object-assign
  • object.assign
  • object.defaults
  • parse-json
  • printf
  • printj
  • q
  • ramda
  • React Native
  • safe-json-parse
  • sanitize
  • sanitizer
  • smart-extend
  • sprintf.js
  • string-template
  • underscore
  • util-extend
  • utils-merge
  • validator
  • xss
  • xtend

• Handling of ambient TypeScript code has been improved. As a result, fewer false positives will be reported in .d.ts files.

New queries

Query	Tags	Purpose
Clear-text logging of sensitive information (js/clear-text-logging)	security, external/cwe/cwe-312, external/cwe/cwe-315, external/cwe/cwe-359	Highlights logging of sensitive information, indicating a violation of CWE-312. Results shown on LGTM by default.
Disabling Electron webSecurity (js/disabling-electron-websecurity)	security, frameworks/electron	Highlights Electron browser objects that are created with the webSecurity property set to false. Results shown on LGTM by default.
Enabling Electron allowRunningInsecureContent (js/enabling-electron-insecure-content)	security, frameworks/electron	Highlights Electron browser objects that are created with the allowRunningInsecureContent property set to true. Results shown on LGTM by default.
Use of externally-controlled format string (js/tainted-format-string)	security, external/cwe/cwe-134	Highlights format strings containing user-provided data, indicating a violation of CWE-134. Results shown on LGTM by default.

Changes to existing queries

Query	Expected impact	Change
Arguments redefined	Fewer results	This rule previously also flagged redefinitions of eval. This was an oversight that is now fixed.
Comparison between inconvertible types	Fewer results	This rule now flags fewer comparisons involving parameters.
Comparison between inconvertible types	Lower severity	The severity of this rule has been revised to "warning".
CORS misconfiguration for credentials transfer	More true-positive results	This rule now treats header names case-insensitively.
Hard-coded credentials	More true-positive results	This rule now recognizes secret cryptographic keys.
Incomplete string escaping or encoding	Better name, more true-positive results	This rule has been renamed to more clearly reflect its purpose. Also, it now recognizes incomplete URL encoding and decoding.
Insecure randomness	More true-positive results	This rule now recognizes secret cryptographic keys.
Misleading indentation after control statement	Fewer results	This rule temporarily ignores TypeScript files.
Missing rate limiting	More true-positive results, fewer false-positive results	This rule now recognizes additional rate limiters and expensive route handlers.
Missing X-Frame-Options HTTP header	Fewer false-positive results	This rule now treats header names case-insensitively.
Omitted array element	Fewer results	This rule temporarily ignores TypeScript files.
Reflected cross-site scripting	Fewer false-positive results	This rule now treats header names case-insensitively.
Semicolon insertion	Fewer results	This rule temporarily ignores TypeScript files.
Server-side URL redirect	More true-positive results	This rule now treats header names case-insensitively.
Superfluous trailing arguments	Fewer false-positive results	This rule now ignores calls to some empty functions.
Type confusion through parameter tampering	Fewer false-positive results	This rule no longer flags emptiness checks.
Uncontrolled command line	More true-positive results	This rule now recognizes indirect command injection through sh -c and similar.
Unused variable	Fewer results	This rule no longer flags class expressions that could be made anonymous. While technically true, these results are not interesting.
Unused variable	Renamed	This rule has been renamed to "Unused variable, import, function or class" to reflect the fact that it flags different kinds of unused program elements.
Use of incompletely initialized object	Fewer results	This rule now flags the constructor instead its errorneous this or super expressions.
Useless conditional	Fewer results	This rule no longer flags uses of boolean return values.
Useless conditional	Fewer results	This rule now flags fewer comparisons involving parameters.

Changes to QL libraries

• HTTP and HTTPS requests made using the Node.js http.request and https.request APIs and the Electron Electron.net.request and Electron.ClientRequest APIs are modeled as RemoteFlowSources.
• HTTP header names are now always normalized to lower case to reflect the fact that they are case insensitive. In particular, the result of HeaderDefinition.getAHeaderName, and the first parameter of HeaderDefinition.defines, ExplicitHeaderDefinition.definesExplicitly and RouteHandler.getAResponseHeader is now always a lower-case string.
• New AST nodes have been added for TypeScript 2.9 and 3.0 features.
• The class JsonParseCall has been deprecated. Use JsonParserCall instead.
• The handling of spread arguments in the data flow library has been changed: DataFlow::InvokeNode.getArgument(i) is now only defined when there is no spread argument at or before argument position i, and similarly InvokeNode.getNumArgument is only defined for invocations without spread arguments.