Catalyst::Plugin::Session before version 0.44 for Perl generates session ids insecurely. The session id is generated from a (usually SHA-1) hash of a simple counter, the epoch time, the built-in rand function, the PID and the current Catalyst context. This information is of low entropy. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

All versions of the package crow are vulnerable to HTTP Response Splitting when untrusted user input is used to build header values. Header values are not properly sanitized against CRLF Injection in the set_header and add_header functions. An attacker can add the \r\n (carriage return line feeds) characters to end the HTTP response headers and inject malicious content.

Versions of Armeria 0.85.0 through and including 0.96.0 are vulnerable to HTTP response splitting, which allows remote attackers to inject arbitrary HTTP headers via CRLF sequences when unsanitized data is used to populate the headers of an HTTP response. This vulnerability has been patched in 0.97.0. Potential impacts of this vulnerability include cross-user defacement, cache poisoning, Cross-site scripting (XSS), and page hijacking.

Netty project is an event-driven asynchronous network application framework. Starting in version 4.1.83.Final and prior to 4.1.86.Final, when calling `DefaultHttpHeadesr.set` with an _iterator_ of values, header value validation was not performed, allowing malicious header values in the iterator to perform HTTP Response Splitting. This issue has been patched in version 4.1.86.Final. Integrators can work around the issue by changing the `DefaultHttpHeaders.set(CharSequence, Iterator<?>)` call, into a `remove()` call, and call `add()` in a loop over the iterator of values.