Executive brief
LibTiff is a widely used library for reading and writing Tag Image File Format (TIFF) files, often utilized by image viewers and document processing software. A vulnerability in this library allows a remote attacker to crash applications that process specially crafted TIFF images. This results in a denial-of-service condition, potentially disrupting business operations or services that handle automated image processing.
Technical details
A NULL pointer dereference exists in the TIFFFetchNormalTag function within tif_dirread.c of LibTiff 4.0.6. The vulnerability is triggered when the library processes TIFF_SETGET_C16ASCII or TIFF_SETGET_C32_ASCII tags that point to 0-byte arrays, leading to an invalid memory access and subsequent process crash. This issue stemmed from an incomplete fix for a previous vulnerability (CVE-2016-9297). An attacker can exploit this by providing a malicious TIFF file to any application linked against the vulnerable library. The issue was resolved in LibTiff version 4.0.7 and various downstream Linux distribution patches.
Affected products
- LibTiff Project LibTiff 4.0.6
Timeline
- 2016-11-16: disclosed: Bug reported to LibTiff Bugzilla (Bug 2593)
- 2016-11-16: patched: Fix committed to LibTiff CVS repository
- 2016-11-18: other: CVE-2016-9448 assigned
- 2017-01-27: advisory: NVD advisory published
References
- http://bugzilla.maptools.org/show_bug.cgi?id=2593
- http://lists.opensuse.org/opensuse-security-announce/2016-12/msg00017.html
- http://www.debian.org/security/2017/dsa-3762
- http://www.openwall.com/lists/oss-security/2016/11/18/15
- http://www.securityfocus.com/bid/94420
- https://security.gentoo.org/glsa/201701-16