vulnerability / NVI-00018463 / Revision 1
@nevware21/ts-utils: Prototype Pollution in objDeepCopy/objCopyProps via for...in without hasOwnProperty
GitHub lists this reviewed advisory for @nevware21/ts-utils. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
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01 / Meaning
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02 / Applicability
The affected context
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@nevware21/ts-utils
source listed<= 0.13.0
## Summary The _copyProps function in lib/src/object/copy.ts uses for...in to iterate over source object properties without an Object.hasOwnProperty check, and does not filter dangerous keys (__proto__, constructor, prototype). This allows an attacker to pollute the prototype chain of all objects in the application. ## Details In _copyProps() (copy.ts lines 186-191), the code iterates all enumerable properties including inherited ones and dangerous keys like __proto__. Any object with a __proto__ key (e.g., from untrusted JSON input) will overwrite the target's prototype. ## PoC ``` const malicious = JSON.parse('{"__proto__": {"polluted": true}}'); objDeepCopy(malicious); console.log({}.polluted); // true ``` ## Suggested Fix Add objHasOwnProperty check and filter __proto__, constructor, prototype keys.
03 / Response
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04 / Limits
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05 / Provenance
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- GHSA-x7j8-49r8-mr43 ↗
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- Revision 1 ·
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