Sink boundary: Input controls object keys that can modify shared prototype state.
The pack does not provide a callable signature for this record; the watched access path is shown directly.
| Arg | Access path | Purpose | Watched |
|---|---|---|---|
| Argument[1] | Argument[1] | The access path Atropos marks for this model. | ▲ sink |
Attacker's-eye view · prototype-pollution
A crafted key such as a prototype path changes defaults or behavior for unrelated objects.
// modeled boundary: Argument[1]
mergeWith(attacker_influenced_value);
1Reject prototype keys.
2Use own-property checks and safe merge APIs.
3Keep parsed data in null-prototype objects where appropriate.
These checks require the surrounding codebase. The model names the boundary; it does not decide reachability or prove that a guard dominates every path.
Is this a bug in your code?Atropos stops here — by design
Atropos identifies Argument[1] as a prototype-pollution sink. It cannot see whether untrusted data reaches this call in your repository.
Lachesis is the codebase-level step: it traces reachability and guards for this symbol.
Check this symbol in Lachesis →Same behavior
●defaultsDeepjavascript●mergejavascript●setjavascript●setWithjavascript●computed-property-writejavascript●plainToClasstypescriptAcross languages
●plainToClasstypescript●plainToInstancetypescript●defaultsDeeptypescript●mergetypescript●mergeWithtypescript●settypescriptWhat neutralizes it
No sanitizer of this kind is modeled.
Model facts · verbatim from the pack
| Role | Kind | Access path | Model ID | Confidence |
|---|---|---|---|---|
| sink | prototype-pollution | Argument[1] | javascript.lodash.mergewith.a1 | medium · corrob. 2 |