BusyBox wget thru 1.3.7 accepted raw CR (0x0D)/LF (0x0A) and other C0 control bytes in the HTTP request-target (path/query), allowing the request line to be split and attacker-controlled headers to be injected. To preserve the HTTP/1.1 request-line shape METHOD SP request-target SP HTTP/1.1, a raw space (0x20) in the request-target must also be rejected (clients should use %20).
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:LI:LA:N6.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N