Data::Entropy versions before 0.010 for Perl read remote entropy sources over plain HTTP.

The Data::Entropy::RawSource::RandomOrg and Data::Entropy::RawSource::RandomnumbersInfo remote sources are accessed over plain HTTP.

The Data::Entropy::RawSource::RandomOrg integrity check trivially matches any non-empty byte string.

Any on-path attacker, such as open WiFi, a compromised ISP, captive portal, or a hostile egress proxy substitutes the response and thereby chooses the bytes returned by randbits and randint for every application that selected one of these sources via withentropysource. The checkbuf method response is equally attacker-controlled, so the retry/sleep behaviour is steerable too.