Poisoned Pipeline / Incidents / AS316
TURKTRUST issued an intermediate CA certificate as if it were a server certificate
In December 2012 Google found a certificate for *.google.com that chained
to TURKTRUST. Two years earlier, in August 2011, TURKTRUST had issued two
certificates through its AÇE Farma Sipariş Sistemi program without
validation. One, *.EGO.GOV.TR, was a normal server certificate. The
other, *.ekoparty.org, was issued as an intermediate CA certificate —
CA:TRUE — instead of an end-entity certificate. Whoever held it could
issue certificates for any domain. The *.ekoparty.org intermediate was
used to mint a *.google.com certificate discovered on 25 December 2012.
Browser vendors blocked the misissued intermediate the same week;
Microsoft's advisory (2798897) and Google's 4 January 2013 post describe
the chain.
Mapped techniques
- T0218 Compromise TLS trust identity
supply-chain TURKTRUST issuance
The private key of the *.ekoparty.org intermediate made its holder
a CA. A google.com certificate minted with it validates in every
browser without the CA's infrastructure ever being touched.