An out-of-bounds write flaw was found in FontForge in versions before 20200314 while parsing SFD files containing certain LayerCount tokens. This flaw allows an attacker to manipulate the memory allocated on the heap, causing the application to crash or execute arbitrary code. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
uiutil.c in FontForge through 20170731 does not validate strings before launching the program specified by the BROWSER environment variable, which might allow remote attackers to conduct argument-injection attacks via a crafted URL, a different vulnerability than CVE-2017-17534.