Executive brief
LibTiff is a widely used software library for reading and writing Tagged Image File Format (TIFF) files. A vulnerability in this library allows a remote attacker to crash applications that process specially crafted image files. This could lead to a service outage or application instability for any software that relies on LibTiff to handle images.
Technical details
An out-of-bounds read vulnerability exists in LibTiff 4.0.6 within the TIFFFetchNormalTag function in tif_dirread.c. The issue stems from a failure to ensure that certain ASCII tags (specifically TIFF_SETGET_C16ASCII and TIFF_SETGET_C32_ASCII) are properly null-terminated. When these malformed tags are processed, subsequent calls to _TIFFPrintField() may read past the end of the allocated buffer. A remote attacker can exploit this by providing a specially crafted TIFF image, leading to an application crash (denial of service). The vulnerability was addressed in version 4.0.7 by ensuring proper null termination of these tag values.
Affected products
- LibTiff LibTiff 4.0.6
Timeline
- 2016-11-11: patched: Fix committed to LibTiff source repository
- 2017-01-13: advisory: Debian security advisory DSA-3762-1 released
- 2017-01-18: disclosed: NVD publication date