During message encoding, hickory-proto's BinEncoder stores pointers to labels that are candidates for name compression in a Vec<(usize, Vec<u8>)>. The name compression logic then searches for matches with a linear scan.
A malicious message with many records can both introduce many candidate labels, and invoke this linear scan many times. This can amplify CPU exhaustion in DoS attacks.
This is similar to CVE-2024-8508.
Qifan Zhang, Palo Alto Networks
0.26.1Exploitability
AV:NAC:LAT:NPR:NUI:NVulnerable System
VC:NVI:NVA:LSubsequent System
SC:NSI:NSA:N6.9/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N