Ubuntu Security Notice 3175-2 – USN-3175-1 fixed vulnerabilities in Firefox. The update caused a regression on systems where the AppArmor profile for Firefox is set to enforce mode. This update fixes the problem. Multiple memory safety issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service via application crash, or execute arbitrary code. JIT code allocation can allow a bypass of ASLR protections in some circumstances. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to cause a denial of service via application crash, or execute arbitrary code. Nicolas GrAgoire discovered a use-after-free when manipulating XSL in XSLT documents in some circumstances. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to cause a denial of service via application crash, or execute arbitrary code. Atte Kettunen discovered a memory corruption issue in Skia in some circumstances. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to cause a denial of service via application crash, or execute arbitrary code. Various other issues were also addressed.