Fix heap-buffer-overflow write in PICT UnpackPictRow#41
Merged
danoli3 merged 1 commit intodanoli3:masterfrom Apr 22, 2026
Merged
Fix heap-buffer-overflow write in PICT UnpackPictRow#41danoli3 merged 1 commit intodanoli3:masterfrom
danoli3 merged 1 commit intodanoli3:masterfrom
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CI failures on macOS/clang are pre-existing — the same 4 checks fail on master (e.g. run on commit a750f88). This PR builds cleanly on Linux and Windows. |
Owner
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Thanks yes I'll make a macOS fix and re-run |
Owner
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Master is fixed could you rebase these and lets test ci |
The PackBits decompression loop in UnpackPictRow advances pCurPixel by the decoded run length without verifying that the destination remains within the allocated line buffer. A crafted PICT file with run lengths that exceed the scanline width causes memset or read_proc to write past the end of pLineBuf. Clamp the decoded length to the remaining buffer space before each write operation, in both the packed-data and unpacked-data code paths. CWE-787 (Out-of-bounds Write) Found during academic security research.
JorgeBarredo14
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Owner
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Thanks running ci now |
Owner
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Amazing merging now. could you update the other prs too |
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Summary
The PackBits decompression loop in
UnpackPictRowadvancespCurPixelby the decoded run length without verifying that the destination remains within the allocated line buffer (pLineBuf, sized torowBytes). A crafted PICT file with run lengths that exceed the scanline width causesmemset(packed path) orread_proc(unpacked path) to write past the end of the buffer.Root cause
PluginPICT.cpplines 562 and 571: the decodedlenis used directly inmemset/read_procwithout clamping to the remaining buffer space.Fix
Clamp the decoded length to the remaining buffer space (
pLineBuf + rowBytes - pCurPixel) before each write operation, in both the packed-data and unpacked-data code paths. Skip the write entirely if no space remains.Metadata