Critical · published May 18, 2023
🚨 A sneaky bytecode optimization bug could let attackers execute arbitrary code in Hermes, and it’s as critical as it gets with a CVSS score of 9.8! 🔥 Think of Hermes like a busy kitchen where chefs are constantly preparing meals. If a chef accidentally leaves a utensil on the counter, it can be picked up by anyone — in this case, that’s the untrusted JavaScript injecting malicious code instead of a delicious dish! An attacker could exploit this vulnerability by executing arbitrary code, potentially taking full control of the application. While many React Native apps are safe due to their trusted environment, if your application executes untrusted JavaScript, the consequences could be absolutely devastating!
Think of Hermes like a busy kitchen where chefs are constantly preparing meals. If a chef accidentally leaves a utensil on the counter, it can be picked up by anyone — in this case, that’s the untrusted JavaScript injecting malicious code instead of a delicious dish! This vulnerability arises from an optimization flaw in Hermes that can lead to a use-after-free condition, allowing an attacker to craft a payload that executes arbitrary code directly within the application. It's a serious issue when untrusted JavaScript is involved.
An attacker could exploit this vulnerability by executing arbitrary code, potentially taking full control of the application. While many React Native apps are safe due to their trusted environment, if your application executes untrusted JavaScript, the consequences could be absolutely devastating! To mitigate this risk, ensure you update Hermes to the latest version that includes the fix from commit e6ed9c1a4b02dc219de1648f44cd808a56171b81. Additionally, review your application's JavaScript execution contexts to avoid running untrusted code. Don't leave any surprises on the counter! You’ve got this! Follow these steps, and you’ll lock it down like a security hero! 🛡️