eMudhra Intermediate CA Compromise
Private keys for eight eMudhra intermediate CA certificates have been compromised, allowing attackers to forge certificates for any site. The keys were revealed due to low entropy, not through a known breach. Browsers blocked them using revocation lists, but other software had to remove the emSign ECC G3 root. Unpatched systems remain exposed to forged certificates, including client auth and…
eMudhra has experienced a security breach, as private keys for eight intermediate Certificate Authority (CA) certificates were exposed. These compromised certificates, used for Transport Layer Security (TLS) and codesigning, were trusted by major web browsers like Apple, Chrome, Microsoft, and Mozilla. Although browsers blocked the affected intermediate CAs through their revocation blocklists, many other software systems lacking such mechanisms remain vulnerable.
To counteract the threat, several projects have removed the eMudhra ECC Root CA - G3 from their trust roots, causing potential disruptions for legitimate certificates issued by those CAs. Forged certificates could be used in man-in-the-middle (MITM) attacks to impersonate websites and services. The compromised private keys were generated using an insecure method, making them easily exploitable compared to large, random numbers.
Eduard "Wayne" Schneider discovered the issue and reported it, leading to updates from various projects such as Mozilla, Arch, Debian, Fedora, Gentoo, Ubuntu, Electron, Go, pip, Python certifi, rustls-webpki, Rust webpki-roots, and uv. However, the widespread use of these compromised CAs in applications, including those relying on system roots or developers' own chosen roots, leaves many systems exposed to potential attacks.
Certificate Transparency and DNS Certificate Authority Authorization (CAA) records could provide additional defenses, but their adoption remains limited.
Written by urgent.news from InfoQ's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
