Fix NULL pointer dereference in outputSWF_TEXT_RECORD (CVE-2018-6315) #103
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In outputSWF_TEXT_RECORD, the array offset is stored in a signed int, while (&(trec->GlyphEntries[i]))->GlyphIndex[0] returns an unsigned 32 bit number. This may lead to an integer overflow when reading the offset from the GlyphIndex array, and further to a buffer overflow when doing buffer[i]=fi->fontcodeptr[off] with negative off. In this commit, we change the type of off to unsigned long so we are guaranteed to be able to store 32 unsigned integers. This commit fixes CVE-2018-6315 (fixes libming#101).
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Thanks, merged.
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Closing the PR since changes have been merged. |
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In outputSWF_TEXT_RECORD, the array offset is stored in a signed int, while
(&(trec->GlyphEntries[i]))->GlyphIndex[0]returns an unsigned 32 bit number.This may lead to an integer overflow when reading the offset from the
GlyphIndexarray, and further to a buffer overflow when doingbuffer[i]=fi->fontcodeptr[off]with negative off.In this commit, we change the type of off to unsigned long so we are guaranteed to be able to store 32 unsigned integers.
This commit fixes CVE-2018-6315 (fixes #101).