Software security has become a highly focused area nowadays. One key problem in this field is to expose software vulnerabilities effectively. Traditional testing methods have shown inadequacy in terms of path coverage and bug detection, due to their reliance on concrete input values. In this paper, we present the idea of combining symbolic execution with runtime annotation checking. By using symbolic input values instead of concrete ones, the specified program properties can be checked on all the corner cases. We introduce two implementations of symbolic runtime annotation checkers: one for C, using the ANSI/ISO C Specification Language, and one for WebAssembly, using the Weasel specification language designed by us. Our approach combines the ease of use and the expressiveness of runtime annotation checking, as well as the power of program analysis.