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Stephan Brandauer
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add handlebars taint step
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‎javascript/ql/lib/semmle/javascript/frameworks/Handlebars.qll‎

Lines changed: 66 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -27,3 +27,69 @@ module Handlebars {
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SafeString() { this = any(Handlebars h).getAConstructorInvocation("SafeString") }
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}
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}
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/** Provides logic for taint steps for the handlebars library. */
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module TaintStep {
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/**
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* Gets a `SourceNode` tracked from a compilation of a Handlebars template.
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*/
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private DataFlow::SourceNode compiledHandlebarsTemplate(DataFlow::Node originalCall) {
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result = compiledHandlebarsTemplate(DataFlow::TypeTracker::end(), originalCall)
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}
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private DataFlow::SourceNode compiledHandlebarsTemplate(
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DataFlow::TypeTracker t, DataFlow::Node originalCall
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) {
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t.start() and
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result = any(Handlebars::Handlebars hb).getAMethodCall(["compile", "template"]) and
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result = originalCall
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or
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exists(DataFlow::TypeTracker t2 |
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result = compiledHandlebarsTemplate(t2, originalCall).track(t2, t)
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)
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}
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/**
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* Holds if there's a step from `pred` to `succ` due to templating data being
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* passed from a templating call to a registered helper via a parameter.
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*/
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private predicate isHandlebarsArgStep(DataFlow::Node pred, DataFlow::Node succ) {
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exists(string helperName |
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exists(DataFlow::CallNode templatingCall, DataFlow::CallNode compileCall |
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templatingCall = compiledHandlebarsTemplate(compileCall).getACall() and
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pred = templatingCall.getAnArgument().getALocalSource().getAPropertyWrite().getRhs() and
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(
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compileCall
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.getArgument(0)
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.mayHaveStringValue(any(string templateText |
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// an approximation: if the template contains the
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// helper name, it's probably a helper call
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templateText.matches("%" + helperName + "%")
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))
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or
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// When we don't have a string value, we can't be sure
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// and will assume a step.
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not exists(string s | compileCall.getArgument(0).mayHaveStringValue(s))
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)
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) and
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exists(DataFlow::CallNode registerHelperCall, DataFlow::FunctionNode helperFunc |
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registerHelperCall = any(Handlebars::Handlebars hb).getAMethodCall("registerHelper") and
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registerHelperCall.getArgument(0).mayHaveStringValue(helperName) and
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helperFunc = registerHelperCall.getArgument(1).getAFunctionValue() and
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helperFunc.getAParameter() = succ
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)
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)
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}
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/**
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* A shared flow step from passing data to a handlebars template with
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* helpers registered.
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*/
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class HandlebarsStep extends DataFlow::SharedFlowStep {
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DataFlow::CallNode templatingCall;
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override predicate step(DataFlow::Node node1, DataFlow::Node node2) {
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isHandlebarsArgStep(node1, node2)
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}
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}
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}

‎javascript/ql/lib/semmle/javascript/security/dataflow/TaintedPathCustomizations.qll‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -850,7 +850,7 @@ module TaintedPath {
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/**
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* Holds if we should include a step from `src -> dst` with labels `srclabel -> dstlabel`, and the
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* standard taint step `src -> dst` should be suppresesd.
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* standard taint step `src -> dst` should be suppressed.
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*/
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private predicate isPosixPathStep(
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DataFlow::Node src, DataFlow::Node dst, Label::PosixPath srclabel, Label::PosixPath dstlabel

‎javascript/ql/test/query-tests/Security/CWE-022/TaintedPath/TaintedPath.expected‎

Lines changed: 45 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1541,6 +1541,25 @@ nodes
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| express.js:8:20:8:32 | req.query.bar |
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| express.js:8:20:8:32 | req.query.bar |
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| express.js:8:20:8:32 | req.query.bar |
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| handlebars.js:19:46:19:60 | req.params.path |
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| handlebars.js:19:46:19:60 | req.params.path |
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| handlebars.js:19:46:19:60 | req.params.path |
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| handlebars.js:19:46:19:60 | req.params.path |
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| handlebars.js:19:46:19:60 | req.params.path |
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| handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name |
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| handlebars.js:31:43:31:57 | req.params.name |
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| handlebars.js:31:43:31:57 | req.params.name |
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| handlebars.js:31:43:31:57 | req.params.name |
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| handlebars.js:31:43:31:57 | req.params.name |
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| normalizedPaths.js:11:7:11:27 | path |
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| normalizedPaths.js:11:7:11:27 | path |
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| normalizedPaths.js:11:7:11:27 | path |
@@ -6414,6 +6433,30 @@ edges
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| TaintedPath.js:211:24:211:30 | req.url | TaintedPath.js:211:14:211:37 | url.par ... , true) |
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| TaintedPath.js:211:24:211:30 | req.url | TaintedPath.js:211:14:211:37 | url.par ... , true) |
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| express.js:8:20:8:32 | req.query.bar | express.js:8:20:8:32 | req.query.bar |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:19:46:19:60 | req.params.path | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:22:18:22:25 | filePath | handlebars.js:23:28:23:35 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| handlebars.js:31:43:31:57 | req.params.name | handlebars.js:22:18:22:25 | filePath |
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| normalizedPaths.js:11:7:11:27 | path | normalizedPaths.js:13:19:13:22 | path |
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| normalizedPaths.js:11:7:11:27 | path | normalizedPaths.js:13:19:13:22 | path |
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| normalizedPaths.js:11:7:11:27 | path | normalizedPaths.js:13:19:13:22 | path |
@@ -9844,6 +9887,8 @@ edges
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| TaintedPath.js:213:45:213:48 | path | TaintedPath.js:211:24:211:30 | req.url | TaintedPath.js:213:45:213:48 | path | This path depends on $@. | TaintedPath.js:211:24:211:30 | req.url | a user-provided value |
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| TaintedPath.js:214:35:214:38 | path | TaintedPath.js:211:24:211:30 | req.url | TaintedPath.js:214:35:214:38 | path | This path depends on $@. | TaintedPath.js:211:24:211:30 | req.url | a user-provided value |
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| express.js:8:20:8:32 | req.query.bar | express.js:8:20:8:32 | req.query.bar | express.js:8:20:8:32 | req.query.bar | This path depends on $@. | express.js:8:20:8:32 | req.query.bar | a user-provided value |
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| handlebars.js:23:28:23:35 | filePath | handlebars.js:19:46:19:60 | req.params.path | handlebars.js:23:28:23:35 | filePath | This path depends on $@. | handlebars.js:19:46:19:60 | req.params.path | a user-provided value |
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| handlebars.js:23:28:23:35 | filePath | handlebars.js:31:43:31:57 | req.params.name | handlebars.js:23:28:23:35 | filePath | This path depends on $@. | handlebars.js:31:43:31:57 | req.params.name | a user-provided value |
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| normalizedPaths.js:13:19:13:22 | path | normalizedPaths.js:11:14:11:27 | req.query.path | normalizedPaths.js:13:19:13:22 | path | This path depends on $@. | normalizedPaths.js:11:14:11:27 | req.query.path | a user-provided value |
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| normalizedPaths.js:14:19:14:29 | './' + path | normalizedPaths.js:11:14:11:27 | req.query.path | normalizedPaths.js:14:19:14:29 | './' + path | This path depends on $@. | normalizedPaths.js:11:14:11:27 | req.query.path | a user-provided value |
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| normalizedPaths.js:15:19:15:38 | path + '/index.html' | normalizedPaths.js:11:14:11:27 | req.query.path | normalizedPaths.js:15:19:15:38 | path + '/index.html' | This path depends on $@. | normalizedPaths.js:11:14:11:27 | req.query.path | a user-provided value |

‎javascript/ql/test/query-tests/Security/CWE-022/TaintedPath/handlebars.js‎

Lines changed: 32 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,32 @@
1+
const express = require('express');
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const hb = require("handlebars");
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const fs = require("fs");
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const app = express();
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const data = {};
8+
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function init() {
10+
data.compiledFileAccess = hb.compile("contents of file {{path}} are: {{catFile path}}")
11+
data.compiledBenign = hb.compile("hello, {{name}}");
12+
data.compiledUnknown = hb.compile(fs.readFileSync("greeting.template"));
13+
hb.registerHelper("catFile", catFile);
14+
}
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init();
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app.get('/some/path1', function (req, res) {
19+
res.send(data.compiledFileAccess({ path: req.params.path })); // NOT ALLOWED (template uses vulnerable catFile)
20+
});
21+
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function catFile(filePath) {
23+
return fs.readFileSync(filePath); // SINK (reads file)
24+
}
25+
26+
app.get('/some/path2', function (req, res) {
27+
res.send(data.compiledBenign({ name: req.params.name })); // ALLOWED (this template does not use catFile)
28+
});
29+
30+
app.get('/some/path3', function (req, res) {
31+
res.send(data.compiledUnknown({ name: req.params.name })); // NOT ALLOWED (could be using vulnerable catFile)
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});

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