Insufficient sanitization of environment variables passed to rsync can bypass the restrictions imposed by rssh, a restricted shell that should restrict users to perform only rsync operations, resulting in the execution of arbitrary shell commands.
Weakness
The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Rssh |
Pizzashack |
2.3.4 (including) |
2.3.4 (including) |
| Rssh |
Ubuntu |
bionic |
* |
| Rssh |
Ubuntu |
cosmic |
* |
| Rssh |
Ubuntu |
trusty |
* |
| Rssh |
Ubuntu |
upstream |
* |
| Rssh |
Ubuntu |
xenial |
* |
Potential Mitigations
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable’s type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.
References