LibreSSL sysadmins should keep an eye on their mirrors for a soon-to-land update.

Announced on Friday, the bug-fix release covers a couple of important vulnerabilities.

The big vuln it plugs is to remove the SSL_OP_SINGLE_DH_USE flag (which meant the operator could be left off), to get rid of a possible man-in-the-middle attack.

Correction: although the flag was deprecated in the release, a later explanatory note says "The actual high severity problem in OpenSSL is not present in LibreSSL, Nor was the CVE in question assigned to LibreSSL."

The LibreSSL release adds root certificates for Comodo RSA Certification Authority and QuoVadis.

As well as a variety of smaller bug-fixes, the LibreSSL group also notes the release introduces changes to the ABI (application binary interface) and API (application programming interface). These, it notes, will stabilise once OpenBSD 5.9 is completed.

“At that time, LibreSSL 2.3.x and 2.2.x will become the stable release branches, and we will drop support for the 2.1.x branch,” the announcement notes.

LibreSSL was created in 2014 in the wake of OpenSSL's notorious Heartbleed vulnerability.

Cisco, which has caught the SSL_OP_SINGLE_DH_USE vulnerability, explains it here. The problem is that the flag allowed the use of unsafe primes when generating Diffie-Hellman parameters.

So far, The Borg hasn't got its software ready for release; it's still in the process of working out which products are affected. ®