The definite_length_decoder function in lib/util/quickder.c in Mozilla Network Security Services (NSS) before 3.16.2.4 and 3.17.x before 3.17.3 does not ensure that the DER encoding of an ASN.1 length is properly formed, which allows remote attackers to conduct data-smuggling attacks by using a long byte sequence for an encoding, as demonstrated by the SEC_QuickDERDecodeItem function's improper handling of an arbitrary-length encoding of 0x00.

Mozilla Network Security Services (NSS) before 3.16.2.1, 3.16.x before 3.16.5, and 3.17.x before 3.17.1, as used in Mozilla Firefox before 32.0.3, Mozilla Firefox ESR 24.x before 24.8.1 and 31.x before 31.1.1, Mozilla Thunderbird before 24.8.1 and 31.x before 31.1.2, Mozilla SeaMonkey before 2.29.1, Google Chrome before 37.0.2062.124 on Windows and OS X, and Google Chrome OS before 37.0.2062.120, does not properly parse ASN.1 values in X.509 certificates, which makes it easier for remote attackers to spoof RSA signatures via a crafted certificate, aka a "signature malleability" issue.

Use-after-free vulnerability in the CERT_DestroyCertificate function in libnss3.so in Mozilla Network Security Services (NSS) 3.x, as used in Firefox before 31.0, Firefox ESR 24.x before 24.7, and Thunderbird before 24.7, allows remote attackers to execute arbitrary code via vectors that trigger certain improper removal of an NSSCertificate structure from a trust domain.