Use-after-free vulnerability in the CERT_DestroyCertificate function in libnss3.so in Mozilla Network Security Services 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.