The non-commercial certificate authority Let’s Encrypt, managed by the community and providing certificates free of charge to anyone interested, has announced the early revocation of about two million TLS certificates, which accounts for approximately 1% of all active certificates from this authority. The revocation of certificates was initiated due to the detection of non-compliance with the specification requirements in the code used by Let’s Encrypt regarding the implementation of the TLS-ALPN-01 extension (RFC 7301, Application-Layer Protocol Negotiation). The non-compliance was related to the absence of certain checks performed during the negotiation of connections based on the TLS ALPN extension used in HTTP/2. Detailed information about the incident will be published after the problematic certificates have been revoked.
On January 26 at 03:48 (MSK), the issue was resolved, but all certificates for which the TLS-ALPN-01 method was used for validation have been decided to be considered invalid. The revocation of certificates will begin on January 28 at 19:00 (MSK). Until that time, users utilizing the TLS-ALPN-01 verification method are recommended to update their certificates; otherwise, they will be declared invalid early.
Relevant notifications regarding the need to update certificates have been sent via email. Users who utilize the Certbot and dehydrated toolkits, with default settings, have not been affected by this issue. The TLS-ALPN-01 method is supported in Caddy, Traefik, apache mod_md, and autocert packages. You can verify the validity of your certificates by searching by identifiers, serial numbers, or domains in the list of problematic certificates.
Since the changes affect behavior during verification using the TLS-ALPN-01 method, updating the ACME client or adjusting settings (Caddy, bitnami/bn-cert, autocert, apache mod_md, Traefik) may be required for continued operation. The changes involve using TLS versions no lower than 1.2 (clients will no longer be able to use TLS 1.1) and the discontinuation of support for OID 1.3.6.1.5.5.7.1.30.1, which identifies the deprecated acmeIdentifier extension supported only in early drafts of RFC 8737 specification (only OID 1.3.6.1.5.5.7.1.31 is now allowed when generating certificates, and clients using OID 1.3.6.1.5.5.7.1.30.1 will not be able to obtain a certificate).
Source: opennet.ru
