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fix: guard AST node property lookups against prototype pollution (fixes #3414) #3470

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37 changes: 26 additions & 11 deletions packages/pug-code-gen/index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -335,7 +335,7 @@ Compiler.prototype = {
}

if (debug && node.debug !== false && node.type !== 'Block') {
if (node.line) {
if (Object.prototype.hasOwnProperty.call(node, 'line') && node.line) {
var js = ';pug_debug_line = ' + node.line;
if (node.filename)
js += ';pug_debug_filename = ' + stringify(node.filename);
Expand Down Expand Up @@ -414,7 +414,7 @@ Compiler.prototype = {
} else {
this.buf.push('case ' + node.expr + ':');
}
if (node.block) {
if (Object.prototype.hasOwnProperty.call(node, 'block') && node.block) {
this.visit(node.block, node);
this.buf.push(' break;');
}
Expand Down Expand Up @@ -450,7 +450,9 @@ Compiler.prototype = {
pp &&
block.nodes.length > 1 &&
!escapePrettyMode &&
Object.prototype.hasOwnProperty.call(block.nodes[0], 'type') &&
block.nodes[0].type === 'Text' &&
Object.prototype.hasOwnProperty.call(block.nodes[1], 'type') &&
block.nodes[1].type === 'Text'
) {
this.prettyIndent(1, true);
Expand All @@ -461,8 +463,11 @@ Compiler.prototype = {
pp &&
i > 0 &&
!escapePrettyMode &&
Object.prototype.hasOwnProperty.call(block.nodes[i], 'type') &&
block.nodes[i].type === 'Text' &&
Object.prototype.hasOwnProperty.call(block.nodes[i - 1], 'type') &&
block.nodes[i - 1].type === 'Text' &&
Object.prototype.hasOwnProperty.call(block.nodes[i - 1], 'val') &&
/\n$/.test(block.nodes[i - 1].val)
) {
this.prettyIndent(1, false);
Expand Down Expand Up @@ -671,11 +676,17 @@ Compiler.prototype = {
}
// if it is non-empty throw an error
if (
tag.code ||
(tag.block &&
(Object.prototype.hasOwnProperty.call(tag, 'code') && tag.code) ||
(Object.prototype.hasOwnProperty.call(tag, 'block') &&
tag.block &&
!(tag.block.type === 'Block' && tag.block.nodes.length === 0) &&
tag.block.nodes.some(function(tag) {
return tag.type !== 'Text' || !/^\s*$/.test(tag.val);
return (
!Object.prototype.hasOwnProperty.call(tag, 'type') ||
tag.type !== 'Text' ||
!Object.prototype.hasOwnProperty.call(tag, 'val') ||
!/^\s*$/.test(tag.val)
);
}))
) {
this.error(
Expand All @@ -696,7 +707,7 @@ Compiler.prototype = {
this.attributeBlocks(tag.attributeBlocks)
);
this.buffer('>');
if (tag.code) this.visitCode(tag.code);
if (Object.prototype.hasOwnProperty.call(tag, 'code') && tag.code) this.visitCode(tag.code);
this.visit(tag.block, tag);

// pretty print
Expand Down Expand Up @@ -807,7 +818,7 @@ Compiler.prototype = {
}

// Block support
if (code.block) {
if (Object.prototype.hasOwnProperty.call(code, 'block') && code.block) {
if (!code.buffer) this.buf.push('{');
this.visit(code.block, code);
if (!code.buffer) this.buf.push('}');
Expand All @@ -826,7 +837,7 @@ Compiler.prototype = {
this.buf.push('if (' + test + ') {');
this.visit(cond.consequent, cond);
this.buf.push('}');
if (cond.alternate) {
if (Object.prototype.hasOwnProperty.call(cond, 'alternate') && cond.alternate) {
if (cond.alternate.type === 'Conditional') {
this.buf.push('else');
this.visitConditional(cond.alternate);
Expand Down Expand Up @@ -1021,12 +1032,16 @@ Compiler.prototype = {
function tagCanInline(tag) {
function isInline(node) {
// Recurse if the node is a block
if (node.type === 'Block') return node.nodes.every(isInline);
if (Object.prototype.hasOwnProperty.call(node, 'type') && node.type === 'Block') return node.nodes.every(isInline);
// When there is a YieldBlock here, it is an indication that the file is
// expected to be included but is not. If this is the case, the block
// must be empty.
if (node.type === 'YieldBlock') return true;
return (node.type === 'Text' && !/\n/.test(node.val)) || node.isInline;
if (Object.prototype.hasOwnProperty.call(node, 'type') && node.type === 'YieldBlock') return true;
return (
(Object.prototype.hasOwnProperty.call(node, 'type') && node.type === 'Text' &&
Object.prototype.hasOwnProperty.call(node, 'val') && !/\n/.test(node.val)) ||
(Object.prototype.hasOwnProperty.call(node, 'isInline') && node.isInline)
);
}

return tag.block.nodes.every(isInline);
Expand Down
18 changes: 15 additions & 3 deletions packages/pug-filters/lib/handle-filters.js
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,21 +6,28 @@ var walk = require('pug-walk');
var error = require('pug-error');
var runFilter = require('./run-filter');

var ownProp = Object.prototype.hasOwnProperty;

module.exports = handleFilters;
function handleFilters(ast, filters, options, filterAliases) {
options = options || {};
walk(
ast,
function(node) {
var dir = node.filename ? dirname(node.filename) : null;
if (node.type === 'Filter') {
if (ownProp.call(node, 'type') && node.type === 'Filter') {
handleNestedFilters(node, filters, options, filterAliases);
var text = getBodyAsText(node);
var attrs = getAttributes(node, options);
attrs.filename = node.filename;
node.type = 'Text';
node.val = filterWithFallback(node, text, attrs);
} else if (node.type === 'RawInclude' && node.filters.length) {
} else if (
ownProp.call(node, 'type') &&
node.type === 'RawInclude' &&
ownProp.call(node, 'filters') &&
node.filters.length
) {
var firstFilter = node.filters.pop();
var attrs = getAttributes(firstFilter, options);
var filename = (attrs.filename = node.file.fullPath);
Expand Down Expand Up @@ -98,7 +105,12 @@ function handleFilters(ast, filters, options, filterAliases) {
}

function handleNestedFilters(node, filters, options, filterAliases) {
if (node.block.nodes[0] && node.block.nodes[0].type === 'Filter') {
if (
ownProp.call(node, 'block') &&
node.block.nodes[0] &&
ownProp.call(node.block.nodes[0], 'type') &&
node.block.nodes[0].type === 'Filter'
) {
node.block.nodes[0] = handleFilters(
node.block,
filters,
Expand Down
61 changes: 41 additions & 20 deletions packages/pug-linker/index.js
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,19 +3,22 @@
var assert = require('assert');
var walk = require('pug-walk');

var ownProp = Object.prototype.hasOwnProperty;

function error() {
throw require('pug-error').apply(null, arguments);
}

module.exports = link;
function link(ast) {
assert(
ast.type === 'Block',
ownProp.call(ast, 'type') && ast.type === 'Block',
'The top level element should always be a block'
);
var extendsNode = null;
if (ast.nodes.length) {
var hasExtends = ast.nodes[0].type === 'Extends';
var hasExtends =
ownProp.call(ast.nodes[0], 'type') && ast.nodes[0].type === 'Extends';
checkExtendPosition(ast, hasExtends);
if (hasExtends) {
extendsNode = ast.nodes.shift();
Expand All @@ -27,11 +30,16 @@ function link(ast) {
var mixins = [];
var expectedBlocks = [];
ast.nodes.forEach(function addNode(node) {
if (node.type === 'NamedBlock') {
if (ownProp.call(node, 'type') && node.type === 'NamedBlock') {
expectedBlocks.push(node);
} else if (node.type === 'Block') {
} else if (ownProp.call(node, 'type') && node.type === 'Block') {
node.nodes.forEach(addNode);
} else if (node.type === 'Mixin' && node.call === false) {
} else if (
ownProp.call(node, 'type') &&
node.type === 'Mixin' &&
ownProp.call(node, 'call') &&
node.call === false
) {
mixins.push(node);
} else {
error(
Expand All @@ -45,7 +53,7 @@ function link(ast) {
extend(parent.declaredBlocks, ast);
var foundBlockNames = [];
walk(parent, function(node) {
if (node.type === 'NamedBlock') {
if (ownProp.call(node, 'type') && node.type === 'NamedBlock') {
foundBlockNames.push(node.name);
}
});
Expand All @@ -71,7 +79,12 @@ function link(ast) {
function findDeclaredBlocks(ast) /*: {[name: string]: Array<BlockNode>}*/ {
var definitions = {};
walk(ast, function before(node) {
if (node.type === 'NamedBlock' && node.mode === 'replace') {
if (
ownProp.call(node, 'type') &&
node.type === 'NamedBlock' &&
ownProp.call(node, 'mode') &&
node.mode === 'replace'
) {
definitions[node.name] = definitions[node.name] || [];
definitions[node.name].push(node);
}
Expand All @@ -82,7 +95,7 @@ function findDeclaredBlocks(ast) /*: {[name: string]: Array<BlockNode>}*/ {
function flattenParentBlocks(parentBlocks, accumulator) {
accumulator = accumulator || [];
parentBlocks.forEach(function(parentBlock) {
if (parentBlock.parents) {
if (ownProp.call(parentBlock, 'parents') && parentBlock.parents) {
flattenParentBlocks(parentBlock.parents, accumulator);
}
accumulator.push(parentBlock);
Expand All @@ -95,7 +108,7 @@ function extend(parentBlocks, ast) {
walk(
ast,
function before(node) {
if (node.type === 'NamedBlock') {
if (ownProp.call(node, 'type') && node.type === 'NamedBlock') {
if (stack[node.name] === node.name) {
return (node.ignore = true);
}
Expand All @@ -106,7 +119,7 @@ function extend(parentBlocks, ast) {
if (parentBlockList.length) {
node.parents = parentBlockList;
parentBlockList.forEach(function(parentBlock) {
switch (node.mode) {
switch (ownProp.call(node, 'mode') ? node.mode : undefined) {
case 'append':
parentBlock.nodes = parentBlock.nodes.concat(node.nodes);
break;
Expand All @@ -122,7 +135,11 @@ function extend(parentBlocks, ast) {
}
},
function after(node) {
if (node.type === 'NamedBlock' && !node.ignore) {
if (
ownProp.call(node, 'type') &&
node.type === 'NamedBlock' &&
!(ownProp.call(node, 'ignore') && node.ignore)
) {
delete stack[node.name];
}
}
Expand All @@ -133,24 +150,24 @@ function applyIncludes(ast, child) {
return walk(
ast,
function before(node, replace) {
if (node.type === 'RawInclude') {
if (ownProp.call(node, 'type') && node.type === 'RawInclude') {
replace({type: 'Text', val: node.file.str.replace(/\r/g, '')});
}
},
function after(node, replace) {
if (node.type === 'Include') {
if (ownProp.call(node, 'type') && node.type === 'Include') {
var childAST = link(node.file.ast);
if (childAST.hasExtends) {
childAST = removeBlocks(childAST);
}
replace(applyYield(childAST, node.block));
replace(applyYield(childAST, ownProp.call(node, 'block') ? node.block : null));
}
}
);
}
function removeBlocks(ast) {
return walk(ast, function(node, replace) {
if (node.type === 'NamedBlock') {
if (ownProp.call(node, 'type') && node.type === 'NamedBlock') {
replace({
type: 'Block',
nodes: node.nodes,
Expand All @@ -163,7 +180,7 @@ function applyYield(ast, block) {
if (!block || !block.nodes.length) return ast;
var replaced = false;
ast = walk(ast, null, function(node, replace) {
if (node.type === 'YieldBlock') {
if (ownProp.call(node, 'type') && node.type === 'YieldBlock') {
replaced = true;
node.type = 'Block';
node.nodes = [block];
Expand All @@ -172,10 +189,14 @@ function applyYield(ast, block) {
function defaultYieldLocation(node) {
var res = node;
for (var i = 0; i < node.nodes.length; i++) {
if (node.nodes[i].textOnly) continue;
if (node.nodes[i].type === 'Block') {
if (ownProp.call(node.nodes[i], 'textOnly') && node.nodes[i].textOnly) continue;
if (ownProp.call(node.nodes[i], 'type') && node.nodes[i].type === 'Block') {
res = defaultYieldLocation(node.nodes[i]);
} else if (node.nodes[i].block && node.nodes[i].block.nodes.length) {
} else if (
ownProp.call(node.nodes[i], 'block') &&
node.nodes[i].block &&
node.nodes[i].block.nodes.length
) {
res = defaultYieldLocation(node.nodes[i].block);
}
}
Expand All @@ -191,7 +212,7 @@ function applyYield(ast, block) {
function checkExtendPosition(ast, hasExtends) {
var legitExtendsReached = false;
walk(ast, function(node) {
if (node.type === 'Extends') {
if (ownProp.call(node, 'type') && node.type === 'Extends') {
if (hasExtends && !legitExtendsReached) {
legitExtendsReached = true;
} else {
Expand Down
23 changes: 15 additions & 8 deletions packages/pug-walk/index.js
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Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
'use strict';

var ownProp = Object.prototype.hasOwnProperty;

module.exports = walkAST;
function walkAST(ast, before, after, options) {
if (after && typeof after === 'object' && typeof options === 'undefined') {
Expand Down Expand Up @@ -34,7 +36,12 @@ function walkAST(ast, before, after, options) {

parents.unshift(ast);

switch (ast.type) {
// Use own-property check to prevent prototype pollution gadgets:
// an attacker could set Object.prototype.type to a node type string,
// causing arbitrary AST branches to be walked on plain objects.
var astType = ownProp.call(ast, 'type') ? ast.type : undefined;

switch (astType) {
case 'NamedBlock':
case 'Block':
ast.nodes = walkAndMergeNodes(ast.nodes);
Expand All @@ -47,28 +54,28 @@ function walkAST(ast, before, after, options) {
case 'When':
case 'Code':
case 'While':
if (ast.block) {
if (ownProp.call(ast, 'block') && ast.block) {
ast.block = walkAST(ast.block, before, after, options);
}
break;
case 'Each':
if (ast.block) {
if (ownProp.call(ast, 'block') && ast.block) {
ast.block = walkAST(ast.block, before, after, options);
}
if (ast.alternate) {
if (ownProp.call(ast, 'alternate') && ast.alternate) {
ast.alternate = walkAST(ast.alternate, before, after, options);
}
break;
case 'EachOf':
if (ast.block) {
if (ownProp.call(ast, 'block') && ast.block) {
ast.block = walkAST(ast.block, before, after, options);
}
break;
case 'Conditional':
if (ast.consequent) {
if (ownProp.call(ast, 'consequent') && ast.consequent) {
ast.consequent = walkAST(ast.consequent, before, after, options);
}
if (ast.alternate) {
if (ownProp.call(ast, 'alternate') && ast.alternate) {
ast.alternate = walkAST(ast.alternate, before, after, options);
}
break;
Expand All @@ -93,7 +100,7 @@ function walkAST(ast, before, after, options) {
case 'Text':
break;
case 'FileReference':
if (options.includeDependencies && ast.ast) {
if (options.includeDependencies && ownProp.call(ast, 'ast') && ast.ast) {
walkAST(ast.ast, before, after, options);
}
break;
Expand Down