| Título | grass 0.13.4 Asymmetric Resource Consumption |
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| Descrição | Grass is a pure-Rust Sass-to-CSS compiler.
`grass` implements Sass's nested parent-selector (`&`) and combinator (`+`, `~`, `>`) semantics. When evaluating rulesets that combine multiple parent-selector references inside child blocks separated by adjacent-sibling
or general-sibling combinators, the resolver in `grass_compiler::selector::extend` and `grass_compiler::evaluate::visitor` recursively materializes the cross-product of every (parent × child) combinator combination.
For adversarial nesting patterns this materialization is super-linear in the number of `&` and combinator tokens, and the per-step Vec allocation overhead is non-trivial. An 85-byte SCSS source is sufficient to drive
grass to allocate ~2.5 GiB of memory and spend ~8 seconds of CPU on a single compilation, against a Sass spec where compile time should be linear in input size.
The compiler does eventually return `Ok(_)`, but the memory and CPU footprint makes any service that compiles untrusted SCSS trivially DoS-able with sub-100-byte payloads. |
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| Fonte | ⚠️ https://github.com/connorskees/grass/issues/117 |
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| Utilizador | Zyz3366 (UID 97230) |
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| Submissão | 03/06/2026 04h42 (há 1 mês) |
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| Moderação | 03/07/2026 20h40 (1 month later) |
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| Estado | Aceite |
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| Entrada VulDB | 376164 [connorskees grass até 0.13.4 visitor Negação de Serviço] |
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| Pontos | 20 |
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