Rule Definition
Whenever a virtual method is defined in a class, it means that the class is intended to be used in an inheritance hierarchy. In this context, a derived object will often be handled through a pointer to its base class, to achieve polymorphism. If a class has a non-virtual destructor, and an attempt is made to destroy an object of a derived type through a pointer to the base type, the behavior is undefined. On some platforms, it may call the base-class version of the destructor instead of the derived-class version, provoking memory leaks, resource losses and stability issues. On others, it may simply crash. Furthermore, once your class contains one virtual function, adding a virtual destructor does not add any additional per-object cost, so adding it is both free and safer.

Remediation
Add a virtual destructor to the class that has a virtual function.

Violation Code Sample

class CParent
{
    ~CParent();
    virtual int foo();
};

Fixed Code Sample

class CParent
{
    virtual ~CParent();
    int virtual foo();
};

"C++ FAQ Lite [20.7] When should my destructor be virtual?":http://www.parashift.com/c++-faq-lite/virtual-functions.html##faq-20.7