CVE-2017-11449

Vulnerability

In ImageMagick before version 7.0.6-1, the coders/mpc.c file does not enable seekable streams for the MPC and CACHE coders. This prevents proper validation of blob sizes, making the coders vulnerable to processing malformed images from unseekable sources such as stdin [1]. The issue affects all versions prior to the fix.

Exploitation

An attacker can exploit this vulnerability by providing a specially crafted image via stdin. No authentication or special network position is required; the attacker simply needs to supply the malicious input to an ImageMagick process that reads from stdin [1].

Impact

Successful exploitation results in a denial of service, causing the application to crash. The description also mentions the possibility of other unspecified impacts, but no further details are provided [1].

Mitigation

The vulnerability is fixed in ImageMagick version 7.0.6-1. The fix involves setting entry->seekable_stream=MagickTrue for the MPC and CACHE coders, as shown in commits [2] and [3]. Users should upgrade to version 7.0.6-1 or later. If upgrading is not possible, avoid processing untrusted images from stdin or other unseekable streams.