An issue was discovered in Arm Mbed TLS before 2.16.6 and 2.7.x before 2.7.15. An attacker that can get precise enough side-channel measurements can recover the long-term ECDSA private key by (1) reconstructing the projective coordinate of the result of scalar multiplication by exploiting side channels in the conversion to affine coordinates; (2) using an attack described by Naccache, Smart, and Stern in 2003 to recover a few bits of the ephemeral scalar from those projective coordinates via several measurements; and (3) using a lattice attack to get from there to the long-term ECDSA private key used for the signatures. Typically an attacker would have sufficient access when attacking an SGX enclave and controlling the untrusted OS.
{
"binaries": [
{
"binary_version": "2.2.1-2ubuntu0.3",
"binary_name": "libmbedcrypto0"
},
{
"binary_version": "2.2.1-2ubuntu0.3",
"binary_name": "libmbedtls-dev"
},
{
"binary_version": "2.2.1-2ubuntu0.3",
"binary_name": "libmbedtls10"
},
{
"binary_version": "2.2.1-2ubuntu0.3",
"binary_name": "libmbedx509-0"
}
]
}
{
"binaries": [
{
"binary_version": "2.16.4-1ubuntu2",
"binary_name": "libmbedcrypto3"
},
{
"binary_version": "2.16.4-1ubuntu2",
"binary_name": "libmbedtls-dev"
},
{
"binary_version": "2.16.4-1ubuntu2",
"binary_name": "libmbedtls12"
},
{
"binary_version": "2.16.4-1ubuntu2",
"binary_name": "libmbedx509-0"
}
]
}