boks_ksllogsd accepts a checksum algorithm name in the MD field of an authenticated KSL start message. Affected releases verify that OpenSSL recognizes the digest name but do not verify that the value fits in a fixed 16-byte checksum context field before copying it. An authenticated KSL client can supply an oversized, OpenSSL-recognized digest name and write beyond the end of the heap allocation.
The attacker must have a valid KSL log-client identity accepted by boks_ksllogsd, network access to the KSL log service, and the ability to send a KSLSTART message with an oversized but OpenSSL-recognized MD value. An unauthenticated network client cannot reach the vulnerable message-processing path.
Upgrade to boks-server 8.1.0.24 or boks-server 9.0.0.7, as appropriate for the installed maintenance line, and ensure the updated boks_ksllogsd is running.