Fix integer overflow in XRef stream byte width parsing#1781
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eddieran wants to merge 1 commit intoHopding:masterfrom
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Fix integer overflow in XRef stream byte width parsing#1781eddieran wants to merge 1 commit intoHopding:masterfrom
eddieran wants to merge 1 commit intoHopding:masterfrom
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The /W array values from XRef streams were read without validation. A crafted PDF with large byte widths (e.g. /W [100, 100, 100]) causes excessive byte reads, integer overflow via bit shifting in parseEntries(), and NaN propagation. This adds: - Validation that each /W byte width is 0-8 per ISO 32000-1:2008, Table 17 - Bounds checking in parseEntries() for premature end of stream Fixes Hopding#1776
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Summary
Fixes #1776 -- integer overflow in XRef stream byte width parsing.
The
/Warray values from XRef streams are read without validation. These widths control loop bounds inparseEntries(). A crafted PDF with/W [100, 100, 100]causes excessive byte reads, integer overflow via bit shifting, and NaN propagation.Changes
/Wbyte widths after reading from the array. Each width must be 0--8 per the PDF spec (ISO 32000-1:2008, Table 17). ThrowsInvalidXRefStreamByteWidthErrorfor out-of-range values.bytes.next()inparseEntries()to gracefully handle premature end-of-stream instead of propagatingundefinedthrough bitwise operations.Files changed
src/core/errors.ts-- newInvalidXRefStreamByteWidthErrorclasssrc/core/parser/PDFXRefStreamParser.ts-- validation + bounds checkingtests/core/parser/PDFXRefStreamParser.spec.ts-- 2 new test casesTest plan
/W [100, 100, 100]throws descriptive error/W [1, 4, 0](valid widths) does not throw