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.
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Http::daemon | Http::daemon_project | * | 6.15 (excluding) |
| Libhttp-daemon-perl | Ubuntu | bionic | * |
| Libhttp-daemon-perl | Ubuntu | devel | * |
| Libhttp-daemon-perl | Ubuntu | esm-infra/xenial | * |
| Libhttp-daemon-perl | Ubuntu | focal | * |
| Libhttp-daemon-perl | Ubuntu | impish | * |
| Libhttp-daemon-perl | Ubuntu | jammy | * |
| Libhttp-daemon-perl | Ubuntu | kinetic | * |
| Libhttp-daemon-perl | Ubuntu | trusty | * |
| Libhttp-daemon-perl | Ubuntu | trusty/esm | * |
| Libhttp-daemon-perl | Ubuntu | upstream | * |
| Libhttp-daemon-perl | Ubuntu | xenial | * |
HTTP requests or responses (“messages”) can be malformed or unexpected in ways that cause web servers or clients to interpret the messages in different ways than intermediary HTTP agents such as load balancers, reverse proxies, web caching proxies, application firewalls, etc. For example, an adversary may be able to add duplicate or different header fields that a client or server might interpret as one set of messages, whereas the intermediary might interpret the same sequence of bytes as a different set of messages. For example, discrepancies can arise in how to handle duplicate headers like two Transfer-encoding (TE) or two Content-length (CL), or the malicious HTTP message will have different headers for TE and CL. The inconsistent parsing and interpretation of messages can allow the adversary to “smuggle” a message to the client/server without the intermediary being aware of it. This weakness is usually the result of the usage of outdated or incompatible HTTP protocol versions in the HTTP agents.