Rust Crates.io Security Advisory
Insufficient validation of outbound header values may lead to request splitting or response splitting attacks in scenarios where attackers have sufficient control over outbound headers.
trillium_http::HeaderName can be constructed infallibly and were not checked for illegal bytes when sending requests. Thus, if an attacker has sufficient control over header values (or names) in a request that they could inject
rn sequences, they could get the client and server out of sync, and then pivot to gain control over other parts of requests or responses. (i.e. exfiltrating data from other requests, SSRF, etc.)
trillium-client >= 0.5.4:
- If any header name or header value is invalid in the client request headers, awaiting the client Conn returns an
Error::MalformedHeaderprior to any network access.
trillium client applications should sanitize or validate untrusted input that is included in header values and header names. Carriage return, newline, and null characters are not allowed.
This only affects use cases where attackers have control of outbound headers, and can insert “rn” sequences. Specifically, if untrusted and unvalidated input is inserted into header names or values.
Discovered and reported by @divergentdave
Advisory available under CC0-1.0