Improper Control of Generation of Code ('Code Injection')
Discuz!ML 3.2 through 3.4 allows remote attackers to execute arbitrary PHP code via a modified language cookie, as demonstrated by changing 4gH4_0df5_language=en to 4gH4_0df5_language=en'.phpinfo().'; (if the random prefix 4gH4_0df5_ were used).
CWE-94 - Code Injection
Code injection is a type of vulnerability that allows an attacker to execute arbitrary code. This vulnerability fully compromises the machine and can cause a wide variety of security issues, such as unauthorized access to sensitive information, manipulation of data, denial of service attacks etc. Code injection is different from command injection in the fact that it is limited by the functionality of the injected language (e.g. PHP), as opposed to command injection, which leverages existing code to execute commands, usually within the context of a shell.