# Changes in TIFF v4.0.7

References
Current Version | v4.0.7 (tag Release-v4-0-7)
Previous Version | v4.0.6
Master Download Site | https://download.osgeo.org/libtiff/
Master HTTP Site #1 | http://www.simplesystems.org/libtiff/
Master HTTP Site #2 | http://libtiff.maptools.org/

This document describes the changes made to the software between the previous and current versions (see above). If you don't find something listed here, then it was not done in this timeframe, or it was not considered important enough to be mentioned. The following information is located here:

## Major changes

- The libtiff tools bmp2tiff, gif2tiff, ras2tiff, sgi2tiff, sgisv, and ycbcr are completely removed from the distribution. these tools were written in the late 1980s and early 1990s for test and demonstration purposes. In some cases the tools were never updated to support updates to the file format, or the file formats are now rarely used. In all cases these tools increased the libtiff security and maintenance exposure beyond the value offered by the tool.

## Software configuration changes

- None

## Library changes

- `libtiff/tif_dirread.c`: in `TIFFFetchNormalTag()`, do not dereference `NULL` pointer when values of tags with `TIFF_SETGET_C16_ASCII` / `TIFF_SETGET_C32_ASCII` access are 0-byte arrays. Fixes MapTools bugzilla #2593 (regression introduced by previous fix done on 2016-11-11 for CVE-2016-9297). Reported by Henri Salo. Assigned as CVE-2016-9448

- `libtiff/tif_aux.c`: fix crash in `TIFFVGetFieldDefaulted()` when requesting Predictor tag and that the zip/lzw codec is not configured. Fixes MapTools bugzilla #2591

- `libtiff/tif_dirread.c`: in `TIFFFetchNormalTag()`, make sure that values of tags with `TIFF_SETGET_C16_ASCII` / `TIFF_SETGET_C32_ASCII` access are `NULL` terminated, to avoid potential read outside buffer in `_TIFFPrintField()`. Fixes MapTools bugzilla #2590

- `libtiff/tif_dirread.c`: reject images with OJPEG compression that have no `TileOffsets`/`StripOffsets` tag, when OJPEG compression is disabled. Prevent `NULL` pointer dereference in `TIFFReadRawStrip1()` and other functions that expect `td_stripbytecount` to be non `NULL`. Fixes MapTools bugzilla #2585

- `libtiff/tif_strip.c`: make `TIFFNumberOfStrips()` return the `td->td_nstrips` value when it is non-zero, instead of recomputing it. This is needed in `TIFF_STRIPCHOP` mode where `td_nstrips` is modified. Fixes a read outsize of array in tiffsplit (or other utilities using `TIFFNumberOfStrips()`). Fixes MapTools bugzilla #2587 (CVE-2016-9273)

- `libtiff/tif_predict.h`, `libtiff/tif_predict.c`: Replace assertions by runtime checks to avoid assertions in debug mode, or buffer overflows in release mode. Can happen when dealing with unusual tile size like YCbCr with subsampling. Reported as MSVR 35105 by Axel Souchet & Vishal Chauhan from the MSRC Vulnerabilities & Mitigations

- `libtiff/tif_dir.c`: discard values of `SMinSampleValue` and `SMaxSampleValue` when they have been read and the value of `SamplesPerPixel` is changed afterwards (like when reading a OJPEG compressed image with a missing `SamplesPerPixel` tag, and whose photometric is `RGB` or `YCbCr`, forcing `SamplesPerPixel` being 3). Otherwise when rewriting the directory (for example with tiffset, we will expect 3 values whereas the array had been allocated with just one), thus causing a out of bound read access. Fixes MapTools bugzilla #2500 (CVE-2014-8127, duplicate: CVE-2016-3658)

- `libtiff/tif_dirwrite.c`: avoid `NULL` pointer dereference on `td_stripoffset` when writing directory, if `FIELD_STRIPOFFSETS` was artificially set for a hack case in OJPEG case. Fixes MapTools bugzilla #2500 (CVE-2014-8127, duplicate: CVE-2016-3658)

- `libtiff/tif_getimage.c` (`TIFFRGBAImageOK()`): Reject attempts to read floating point images.

- `libtiff/tif_predict.c` (`PredictorSetup()`): Enforce bits-per-sample requirements of floating point predictor (3). Fixes CVE-2016-3622 "Divide By Zero in the tiff2rgba tool."

- `libtiff/tif_pixarlog.c`: fix out-of-bounds write vulnerabilities in heap allocated buffers. Reported as MSVR 35094. Discovered by Axel Souchet and Vishal Chauhan from the MSRC Vulnerabilities & Mitigations team.

- `libtiff/tif_write.c`: fix issue in error code path of `TIFFFlushData1()` that didn't reset the `tif_rawcc` and `tif_rawcp` members. I'm not completely sure if that could happen in practice outside of the odd behaviour of `t2p_seekproc()` of tiff2pdf). The report points that a better fix could be to check the return value of `TIFFFlushData1()` in places where it isn't done currently, but it seems this patch is enough. Reported as MSVR 35095. Discovered by Axel Souchet & Vishal Chauhan & Suha Can from the MSRC Vulnerabilities & Mitigations team.

- `libtiff/tif_pixarlog.c`: Fix write buffer overflow in `PixarLogEncode()` if more input samples are provided than expected by `PixarLogSetupEncode()`. Idea based on `libtiff-CVE-2016-3990.patch` from `libtiff-4.0.3-25.el7_2.src.rpm` by Nikola Forro, but with different and simpler check. (MapTools bugzilla #2544)

- `libtiff/tif_read.c`: Fix out-of-bounds read on memory-mapped files in `TIFFReadRawStrip1()` and `TIFFReadRawTile1()` when `stripoffset` is beyond `tmsize_t` max value (reported by Mathias Svensson)

- `libtiff/tif_read.c`: make `TIFFReadEncodedStrip()` and `TIFFReadEncodedTile()` directly use user provided buffer when no compression (and other conditions) to save a `memcpy()`

- `libtiff/tif_write.c`: make `TIFFWriteEncodedStrip()` and `TIFFWriteEncodedTile()` directly use user provided buffer when no compression to save a `memcpy()`.

- `libtiff/tif_luv.c`: validate that for `COMPRESSION_SGILOG` and `PHOTOMETRIC_LOGL`, there is only one sample per pixel. Avoid potential invalid memory write on corrupted/unexpected images when using the `TIFFRGBAImageBegin()` interface (reported by Clay Wood)

- `libtiff/tif_pixarlog.c`: fix potential buffer write overrun in `PixarLogDecode()` on corrupted/unexpected images (reported by Mathias Svensson) (CVE-2016-5875)

- libtiff/libtiff.def: Added `_TIFFMultiply32` and `_TIFFMultiply64` to libtiff.def

- `libtiff/tif_config.vc.h` (`HAVE_SNPRINTF`): Add a '1' to the `HAVE_SNPRINTF` definition.

- `libtiff/tif_config.vc.h` (`HAVE_SNPRINTF`): Applied patch by Edward Lam to define `HAVE_SNPRINTF` for Visual Studio 2015.

- `libtiff/tif_dirread.c`: when compiled with `DEFER_STRILE_LOAD`, fix regression, introduced on 2014-12-23, when reading a one-strip file without a `StripByteCounts` tag. GDAL #6490

- `libtiff/*`: upstream typo fixes (mostly contributed by Kurt Schwehr) coming from GDAL internal libtiff

- `libtiff/tif_fax3.h`: make `Param` member of `TIFFFaxTabEnt` structure a `uint16` to reduce size of the binary.

- `libtiff/tif_read.c`, `tif_dirread.c`: fix indentation issues raised by GCC 6 `-Wmisleading-indentation`

- `libtiff/tif_pixarlog.c`: avoid zlib error messages to pass a `NULL` string to `%s` formatter, which is undefined behaviour in `sprintf()`.

- `libtiff/tif_next.c`: fix potential out-of-bound write in `NeXTDecode()` triggered by http://lcamtuf.coredump.cx/afl/vulns/libtiff5.tif (MapTools bugzilla #2508)

- `libtiff/tif_luv.c`: fix potential out-of-bound writes in decode functions in non debug builds by replacing `assert()` by regular `if` checks (MapTools bugzilla #2522). Fix potential out-of-bound reads in case of short input data.

- `libtiff/tif_getimage.c`: fix out-of-bound reads in `TIFFRGBAImage` interface in case of unsupported values of `SamplesPerPixel`/`ExtraSamples` for LogLUV / CIELab. Add explicit call to `TIFFRGBAImageOK()` in `TIFFRGBAImageBegin()`. Fix CVE-2015-8665 reported by limingxing and CVE-2015-8683 reported by zzf of Alibaba.

- `libtiff/tif_dirread.c`: workaround false positive warning of Clang Static Analyzer about `NULL` pointer dereference in `TIFFCheckDirOffset()`.

- `libtiff/tif_fax3.c`: remove dead assignment in `Fax3PutEOLgdal()`. Found by Clang Static Analyzer

- `libtiff/tif_dirwrite.c`: fix truncation to 32 bit of file offsets in `TIFFLinkDirectory()` and `TIFFWriteDirectorySec()` when aligning directory offsets on a even offset (affects BigTIFF). This was a regression of the changeset of 2015-10-19.

- `libtiff/tif_write.c`: `TIFFWriteEncodedStrip()` and `TIFFWriteEncodedTile()` should return -1 in case of failure of `tif_encodestrip()` as documented

- `libtiff/tif_dumpmode.c`: `DumpModeEncode()` should return 0 in case of failure so that the above mentioned functions detect the error.

- `libtiff/*.c`: fix MSVC warnings related to cast shortening and assignment within conditional expression

- `libtiff/*.c`: fix clang -Wshorten-64-to-32 warnings

- `libtiff/tif_dirread.c`: prevent reading ColorMap or TransferFunction if `BitsPerPixel` > 24, so as to avoid huge memory allocation and file read attempts

- `libtiff/tif_dirread.c`: remove duplicated assignment (reported by Clang static analyzer)

- `libtiff/tif_dir.c`, `libtiff/tif_dirinfo.c`, `libtiff/tif_compress.c`, `libtiff/tif_jpeg_12.c`: suppress warnings about 'no previous declaration/prototype'

- `libtiff/tiffiop.h`, `libtiff/tif_dirwrite.c`: suffix constants by U to fix 'warning: negative integer implicitly converted to unsigned type' warning (part of `-Wconversion`)

- `libtiff/tif_dir.c`, `libtiff/tif_dirread.c`, `libtiff/tif_getimage.c`, `libtiff/tif_print.c`: fix `-Wshadow` warnings (only in `libtiff/`)

## Tools changes

- tools/Makefile.am: The libtiff tools bmp2tiff, gif2tiff, ras2tiff, sgi2tiff, sgisv, and ycbcr are completely removed from the distribution. The libtiff tools rgb2ycbcr and thumbnail are only built in the build tree for testing. Old files are put in new `archive` subdirectory of the source repository, but not in distribution archives. These changes are made in order to lessen the maintenance burden.

- `tools/tiff2pdf.c`: avoid undefined behaviour related to overlapping of source and destination buffer in `memcpy()` call in `t2p_sample_rgbaa_to_rgb()` Fixes MapTools bugzilla #2577

- `tools/tiff2pdf.c`: fix potential integer overflows on 32 bit builds in `t2p_read_tiff_size()` Fixes MapTools bugzilla #2576

- `tools/fax2tiff.c`: fix segfault when specifying `-r` without argument. Patch by Yuriy M. Kaminskiy. Fixes MapTools bugzilla #2572

- `tools/tiffinfo.c`: fix out-of-bound read on some tiled images. (MapTools bugzilla #2517)

- `tools/tiffcrop.c`: fix multiple uint32 overflows in `writeBufferToSeparateStrips()`, `writeBufferToContigTiles()` and `writeBufferToSeparateTiles()` that could cause heap buffer overflows. Reported by Henri Salo from Nixu Corporation. Fixes MapTools bugzilla #2592

- `tools/tiffcrop.c`: fix out-of-bound read of up to 3 bytes in `readContigTilesIntoBuffer()`. Reported as MSVR 35092 by Axel Souchet & Vishal Chauhan from the MSRC Vulnerabilities & Mitigations team.

- `tools/tiff2pdf.c`: fix write buffer overflow of 2 bytes on JPEG compressed images. Reported by Tyler Bohan of Cisco Talos as TALOS-CAN-0187 / CVE-2016-5652. Also prevents writing 2 extra uninitialized bytes to the file stream.

- `tools/tiffcp.c`: fix out-of-bounds write on tiled images with odd tile width vs image width. Reported as MSVR 35103 by Axel Souchet and Vishal Chauhan from the MSRC Vulnerabilities & Mitigations team.

- `tools/tiff2pdf.c`: fix read -largely- outsize of buffer in `t2p_readwrite_pdf_image_tile()`, causing crash, when reading a JPEG compressed image with `TIFFTAG_JPEGTABLES` length being one. Reported as MSVR 35101 by Axel Souchet and Vishal Chauhan from the MSRC Vulnerabilities & Mitigations team.

- `tools/tiffcp.c`: fix read of undefined variable in case of missing required tags. Found on test case of MSVR 35100.

- `tools/tiffcrop.c`: fix read of undefined buffer in `readContigStripsIntoBuffer()` due to uint16 overflow. Probably not a security issue but I can be wrong. Reported as MSVR 35100 by Axel Souchet from the MSRC Vulnerabilities & Mitigations team.

- `tools/tiffcrop.c`: fix various out-of-bounds write vulnerabilities in heap or stack allocated buffers. Reported as MSVR 35093, MSVR 35096 and MSVR 35097. Discovered by Axel Souchet and Vishal Chauhan from the MSRC Vulnerabilities & Mitigations team.

- `tools/tiff2pdf.c`: fix out-of-bounds write vulnerabilities in heap allocate buffer in `t2p_process_jpeg_strip()`. Reported as MSVR 35098. Discovered by Axel Souchet and Vishal Chauhan from the MSRC Vulnerabilities & Mitigations team.

- `tools/tiff2bw.c`: fix weight computation that could result of color value overflow (no security implication). Fix MapTools bugzilla #2550. Patch by Frank Freudenberg.

- `tools/rgb2ycbcr.c`: validate values of `-v` and `-h` parameters to avoid potential divide by zero. Fixes CVE-2016-3623 (MapTools bugzilla #2569)

- `tools/tiffcrop.c`: Fix out-of-bounds write in `loadImage()`. From patch `libtiff-CVE-2016-3991.patch` from `libtiff-4.0.3-25.el7_2.src.rpm` by Nikola Forro (MapTools bugzilla #2543)

- `tools/tiff2rgba.c`: Fix integer overflow in size of allocated buffer, when `-b` mode is enabled, that could result in out-of-bounds write. Based initially on patch `tiff-CVE-2016-3945.patch` from `libtiff-4.0.3-25.el7_2.src.rpm` by Nikola Forro, with correction for invalid tests that rejected valid files. (MapTools bugzilla #2545)

- `tools/tiffcrop.c`: Avoid access outside of stack allocated array on a tiled separate TIFF with more than 8 samples per pixel. Reported by Kaixiang Zhang of the Cloud Security Team, Qihoo 360 (CVE-2016-5321 / CVE-2016-5323 , MapTools bugzilla #2558 / MapTools bugzilla #2559)

- `tools/tiffdump.c`: fix a few misaligned 64-bit reads warned by `-fsanitize`

- `tools/tiffdump.c` (`ReadDirectory()`): Remove `uint32` cast to `_TIFFmalloc()` argument which resulted in Coverity report. Added more mutiplication overflow checks.

## Contributed software changes

None