CyberRota Analysis
AI-GeneratedUnbound versions 1.7.0 through 1.25.1 are vulnerable when the 'dnscrypt:' clause contains more 'dnscrypt-provider-cert:' files than corresponding 'dnscrypt-secret-key:' files, leading to potential server crashes due to garbage data dereferencing. This issue can be exploited by any unauthenticated client sending a specific UDP datagram, resulting in a denial of service. Organizations using Unbound with DNSCrypt support should prioritize patching this vulnerability to prevent potential service disruptions.
Original NVD Description
In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when the 'dnscrypt:' clause lists more 'dnscrypt-provider-cert:' files than there are matching 'dnscrypt-secret-key:' files, Unbound fills only the matched prefix and leaves the tail slots at the '0xdb' fill that libsodium's allocator writes into every allocation. Unbound would then iterate over the number of cert files, not the actual slots, so it walks into a slot with garbage data filled with '0xdb' bytes. Any unauthenticated client that sends one UDP datagram of ≥ 68 bytes whose first 8 bytes are '0xdb' to 'dnscrypt-port' will use that garbage entry which leads to a garbage dereference killing the server. This is a silent faulty configuration that goes unnoticed until triggered with the right client query. Unbound needs to be compiled with DNSCrypt support ('--enable-dnscrypt').
Related CVEs
Other vulnerabilities affecting the same vendor(s)