Traefik versions before v2.11.55 contain an authentication bypass vulnerability in the digestAuth middleware where unknown usernames receive an empty secret instead of rejection. Attackers can compute a valid digest response using the empty secret and arbitrary credentials to bypass authentication on any digestAuth-protected route without a valid username or password.
Exploitability
AV:NAC:LAT:NPR:NUI:NVulnerable System
VC:HVI:HVA:HSubsequent System
SC:NSI:NSA:N9.3/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NAuthentication