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.

The sec_asn1d_parse_leaf function 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, improperly restricts access to an unspecified data structure, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via crafted OCTET STRING data, related to a "use-after-poison" issue.

Mozilla Network Security Services (NSS) before 3.19.1, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, and other products, does not properly perform Elliptical Curve Cryptography (ECC) multiplications, which makes it easier for remote attackers to spoof ECDSA signatures via unspecified vectors.

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state machine, which allows man-in-the-middle attackers to defeat cryptographic protection mechanisms by blocking messages, as demonstrated by removing a forward-secrecy property by blocking a ServerKeyExchange message, aka a "SMACK SKIP-TLS" issue.

The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.

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.

The cert_TestHostName function in lib/certdb/certdb.c in the certificate-checking implementation in Mozilla Network Security Services (NSS) before 3.16 accepts a wildcard character that is embedded in an internationalized domain name's U-label, which might allow man-in-the-middle attackers to spoof SSL servers via a crafted certificate.

Mozilla Network Security Services (NSS) before 3.15.4, as used in Mozilla Firefox before 27.0, Firefox ESR 24.x before 24.3, Thunderbird before 24.3, SeaMonkey before 2.24, and other products, does not properly restrict public values in Diffie-Hellman key exchanges, which makes it easier for remote attackers to bypass cryptographic protection mechanisms in ticket handling by leveraging use of a certain value.