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fix(dotenv): prevent prototype pollution during parsing #6661

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Merged
merged 2 commits into from
May 23, 2025
Merged

fix(dotenv): prevent prototype pollution during parsing #6661

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96f3052
fix(dotenv): prevent prototype pollution during parsing
lucacasonato May 20, 2025
f90a810
add test case
kt3k May 23, 2025
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2 changes: 1 addition & 1 deletion dotenv/parse.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -74,7 +74,7 @@ function expand(str: string, variablesMap: { [key: string]: string }): string {
* @returns The parsed object.
*/
export function parse(text: string): Record<string, string> {
const env: Record<string, string> = {};
const env: Record<string, string> = Object.create(null);

let match;
const keysForExpandCheck = [];
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8 changes: 8 additions & 0 deletions dotenv/parse_test.ts
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Expand Up @@ -276,3 +276,11 @@ Deno.test("parse() expands variables", () => {
"variables within and without brackets expanded",
);
});

Deno.test("parse() result is not affected by extended Object.prototype", () => {
// deno-lint-ignore no-explicit-any
(Object.prototype as any).foo = 1;
const result = parse("bar=1");
assertEquals(result.foo, undefined);
assertEquals(result.bar, "1");
});
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