HTTP::Daemon is a simple http server class written in perl. Versions prior to 6.15 are subject to a vulnerability which could potentially be exploited to gain privileged access to APIs or poison intermediate caches. It is uncertain how large the risks are, most Perl based applications are served on top of Nginx or Apache, not on the `HTTP::Daemon`. This library is commonly used for local development and tests. Users are advised to update to resolve this issue. Users unable to upgrade may add additional request handling logic as a mitigation. After calling `my $rqst = $conn->get_request()` one could inspect the returned `HTTP::Request` object. Querying the 'Content-Length' (`my $cl = $rqst->header('Content-Length')`) will show any abnormalities that should be dealt with by a `400` response. Expected strings of 'Content-Length' SHOULD consist of either a single non-negative integer, or, a comma separated repetition of that number. (that is `42` or `42, 42, 42`). Anything else MUST be rejected.

• https://github.com/libwww-perl/HTTP-Daemon/commit/e84475de51d6fd7b29354a997413472a99db70b2
• https://github.com/libwww-perl/HTTP-Daemon/commit/8dc5269d59e2d5d9eb1647d82c449ccd880f7fd0
• https://portswigger.net/research/http-desync-attacks-request-smuggling-reborn
• https://datatracker.ietf.org/doc/html/rfc7230#section-9.5
• https://github.com/libwww-perl/HTTP-Daemon/security/advisories/GHSA-cg8c-pxmv-w7cf
• http://metacpan.org/release/HTTP-Daemon/
• https://cwe.mitre.org/data/definitions/444.html
• https://github.com/libwww-perl/HTTP-Daemon/issues/56
• https://github.com/NixOS/nixpkgs/pull/181632

HTTP::Daemon versions before 6.17 for Perl allow OS command injection via send_file(). send_file() opens its string argument with Perl's 2-arg open(). The 2-arg form interprets magic prefixes: '| cmd' and 'cmd |' open a pipe to a subprocess, '> path' and '>> path' open the path for write or append. Untrusted input passed to send_file() can run OS commands at the daemon process UID. The read-pipe form ('cmd |') also leaks subprocess stdout into the HTTP response body. The write-mode forms can create or truncate files at attacker chosen paths.

• https://github.com/libwww-perl/HTTP-Daemon/pull/89
• https://github.com/libwww-perl/HTTP-Daemon/commit/945d35141d94490f749640bd4390acd6a2193995.patch
• https://metacpan.org/release/OALDERS/HTTP-Daemon-6.17/changes