LiquidJS has a memory and render limit bypass via unbounded width padding in `date` filter (strftime)

• <= 10.25.7

## Summary The `date` filter's strftime implementation parses width specifiers like `%9999999d` and forwards the captured width unchecked into `pad()`/`padStart()` in `src/util/underscore.ts`. The pad loop performs unbounded string concatenation without consulting the Context's `memoryLimit` or `renderLimit`, so a single small template (`{{ x | date: '%5000000d' }}`) produces megabytes of output and unbounded CPU. The `memoryLimit` and `renderLimit` options the docs (`src/liquid-options.ts:87-92`) advertise as DoS controls — and which the docstring explicitly mentions for `strftime` — are entirely bypassed. ## Details `date.ts:5-13` only charges `memoryLimit` for the lengths of the input value, format string, and timezone: ```ts export function date (this: FilterImpl, v: string | Date, format?: string, timezoneOffset?: number | string) { const size = ((v as string)?.length ?? 0) + (format?.length ?? 0) + ((timezoneOffset as string)?.length ?? 0) this.context.memoryLimit.use(size) ... return strftime(date, format) } ``` `strftime` (`src/util/strftime.ts:121`) then walks the format with `rFormat = /%([-_0^#:]+)?(\d+)?([EO])?(.)/`. The captured `width` group is passed dir

GitHub Advisory Database

• SEMVER: introduced 0; fixed 10.26.0

## Summary The `date` filter's strftime implementation parses width specifiers like `%9999999d` and forwards the captured width unchecked into `pad()`/`padStart()` in `src/util/underscore.ts`. The pad loop performs unbounded string concatenation without consulting the Context's `memoryLimit` or `renderLimit`, so a single small template (`{{ x | date: '%5000000d' }}`) produces megabytes of output and unbounded CPU. The `memoryLimit` and `renderLimit` options the docs (`src/liquid-options.ts:87-92`) advertise as DoS controls — and which the docstring explicitly mentions for `strftime` — are entirely bypassed. ## Details `date.ts:5-13` only charges `memoryLimit` for the lengths of the input value, format string, and timezone: ```ts export function date (this: FilterImpl, v: string | Date, format?: string, timezoneOffset?: number | string) { const size = ((v as string)?.length ?? 0) + (format?.length ?? 0) + ((timezoneOffset as string)?.length ?? 0) this.context.memoryLimit.use(size) ... return strftime(date, format) } ``` `strftime` (`src/util/strftime.ts:121`) then walks the format with `rFormat = /%([-_0^#:]+)?(\d+)?([EO])?(.)/`. The captured `width` group is passed dir

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