Heap-based buffer overflow in the ASN.1 decoder in Mozilla Network Security Services (NSS) before 3.19.2.1 and 3.20.x before 3.20.1, as used in Firefox before 42.0 and Firefox ESR 38.x before 38.4 and other products, allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via crafted OCTET STRING data.

Mozilla Firefox could allow a remote attacker to execute arbitrary code on the system, caused by a use-after-poison in the secasn1dparseleaf() function. By persuading a victim to visit a specially-crafted Web site, a remote attacker could exploit this vulnerability using unknown attack vectors to execute arbitrary code on the vulnerable system or cause a denial of service.

Integer overflow in the PLARENAALLOCATE implementation in Netscape Portable Runtime (NSPR) in Mozilla Network Security Services (NSS) before 3.19.2.1 and 3.20.x before 3.20.1, as used in Firefox before 42.0 and Firefox ESR 38.x before 38.4 and other products, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via unspecified vectors.