Angular Expressions - Remote Code Execution

Vulnerability Description

angular-expressions is "angular's nicest part extracted as a standalone module for the browser and node". In angular-expressions before version 1.1.2 there is a vulnerability which allows Remote Code Execution if you call "expressions.compile(userControlledInput)" where "userControlledInput" is text that comes from user input. The security of the package could be bypassed by using a more complex payload, using a ".constructor.constructor" technique. In terms of impact: If running angular-expressions in the browser, an attacker could run any browser script when the application code calls expressions.compile(userControlledInput). If running angular-expressions on the server, an attacker could run any Javascript expression, thus gaining Remote Code Execution. This is fixed in version 1.1.2 of angular-expressions A temporary workaround might be either to disable user-controlled input that will be fed into angular-expressions in your application or allow only following characters in the userControlledInput.

References

• https://github.com/peerigon/angular-expressions/security/advisories/GHSA-j6px-jwvv-vpwq
• https://www.npmjs.com/package/angular-expressions
• http://blog.angularjs.org/2016/09/angular-16-expression-sandbox-removal.html
• https://github.com/peerigon/angular-expressions/commit/07edb62902b1f6127b3dcc013da61c6316dd0bf1