Описание
When decoding an OpenEXR file that uses DWAA or DWAB compression, there's an implicit assumption that all image channels have the same pixel type (and size), and that if there are four channels, the first four are "B", "G", "R" and "A". The channel parsing code can be found in decode_header. The buffer td->uncompressed_data is allocated in decode_block based on the xsize, ysize and computed current_channel_offset.
The function dwa_uncompress then assumes at [5] that if there are 4 channels, these are "B", "G", "R" and "A", and in the calculations at [6] and [7] that all channels are of the same type, which matches the type of the main color channels.
If we set the main color channels to a 4-byte type and add duplicate or unknown channels of the 2-byte EXR_HALF type, then the addition at [7] will increment the pointer by 4-bytes * xsize * nb_channels, which will exceed the allocated buffer.
We recommend upgrading to version 8.0 or beyond.
A flaw was found in FFmpeg. This vulnerability allows a buffer overflow via a specially crafted OpenEXR (EXR) file using DWAA (DreamWorks Animation Adaptive) or DWAB (DreamWorks Animation B-wave) compression, due to incorrect handling of image channel pixel types during decoding.
Отчет
The highest threat is to system availability, as processing a specially crafted OpenEXR file with DWAA/DWAB compression can lead to a buffer overflow in FFmpeg, resulting in a denial of service. This requires an attacker to be on the same adjacent network.
Дополнительная информация
Статус:
6.5 Medium
CVSS3
Связанные уязвимости
When decoding an OpenEXR file that uses DWAA or DWAB compression, there's an implicit assumption that all image channels have the same pixel type (and size), and that if there are four channels, the first four are "B", "G", "R" and "A". The channel parsing code can be found in decode_header. The buffer td->uncompressed_data is allocated in decode_block based on the xsize, ysize and computed current_channel_offset. The function dwa_uncompress then assumes at [5] that if there are 4 channels, these are "B", "G", "R" and "A", and in the calculations at [6] and [7] that all channels are of the same type, which matches the type of the main color channels. If we set the main color channels to a 4-byte type and add duplicate or unknown channels of the 2-byte EXR_HALF type, then the addition at [7] will increment the pointer by 4-bytes * xsize * nb_channels, which will exceed the allocated buffer. We recommend upgrading to version 8.0 or beyond.
When decoding an OpenEXR file that uses DWAA or DWAB compression, there's an implicit assumption that all image channels have the same pixel type (and size), and that if there are four channels, the first four are "B", "G", "R" and "A". The channel parsing code can be found in decode_header. The buffer td->uncompressed_data is allocated in decode_block based on the xsize, ysize and computed current_channel_offset. The function dwa_uncompress then assumes at [5] that if there are 4 channels, these are "B", "G", "R" and "A", and in the calculations at [6] and [7] that all channels are of the same type, which matches the type of the main color channels. If we set the main color channels to a 4-byte type and add duplicate or unknown channels of the 2-byte EXR_HALF type, then the addition at [7] will increment the pointer by 4-bytes * xsize * nb_channels, which will exceed the allocated buffer. We recommend upgrading to version 8.0 or beyond.
When decoding an OpenEXR file that uses DWAA or DWAB compression, ther ...
When decoding an OpenEXR file that uses DWAA or DWAB compression, there's an implicit assumption that all image channels have the same pixel type (and size), and that if there are four channels, the first four are "B", "G", "R" and "A". The channel parsing code can be found in decode_header. The buffer td->uncompressed_data is allocated in decode_block based on the xsize, ysize and computed current_channel_offset. The function dwa_uncompress then assumes at [5] that if there are 4 channels, these are "B", "G", "R" and "A", and in the calculations at [6] and [7] that all channels are of the same type, which matches the type of the main color channels. If we set the main color channels to a 4-byte type and add duplicate or unknown channels of the 2-byte EXR_HALF type, then the addition at [7] will increment the pointer by 4-bytes * xsize * nb_channels, which will exceed the allocated buffer. We recommend upgrading to version 8.0 or beyond.
Уязвимость функции dwa_uncompress() компонента OpenEXR File Decoder мультимедийной библиотеки FFmpeg, позволяющая нарушителю выполнить произвольный код
6.5 Medium
CVSS3