M6: Flawed Cryptography
Learn about the risks of Flawed Cryptography in mobile apps, how to prevent it, and examples of attack scenarios. Take necessary precautions to protect sensitive data.
Overview
Flawed Cryptography refers to the vulnerability that arises when encryption processes are implemented improperly or when weak encryption algorithms are used. It can result in the unauthorized retrieval of sensitive information from the device and can have various business impacts such as privacy violations, information theft, and reputational damage.
Description
Flawed Cryptography is a prevalent threat in mobile apps that employ encryption. This vulnerability can manifest in two primary ways. Firstly, the encryption/decryption process implemented in the mobile app may be inherently flawed, allowing an adversary to exploit it and decrypt sensitive data. Secondly, the app may use weak encryption algorithms that can be easily decrypted by an adversary. This vulnerability can have severe technical and business impacts, leading to the unauthorized retrieval of sensitive information and potential harm to the business's reputation.
How to Prevent ?
To prevent Flawed Cryptography, it is crucial to adhere to best practices for encryption. This involves using modern and robust encryption algorithms accepted by the security community. Additionally, proper key management processes should be implemented to ensure that the keys are inaccessible to attackers. Avoid using hardcoded keys within the binary, and store the keys separately from the encrypted content. Custom encryption protocols should be avoided, and it is recommended to leverage the encryption APIs provided by the mobile platform. Insecure and deprecated algorithms such as RC2, MD4, MD5, and SHA1 should not be used. Regular security assessments and testing should be conducted to identify and address any vulnerabilities related to Flawed Cryptography.
Example Attack Scenarios:
Reverse Engineering of iOS app: An attacker with a jailbroken device can use tools like ClutchMod or GBD to download and snapshot the decrypted app from memory. They can then perform static/dynamic analysis and conduct binary attacks to exploit vulnerabilities related to Flawed Cryptography.
Key Interception via Binary Attacks: In cases where the keys are stored within the binary, an attacker can intercept them through binary attacks. This can lead to the unauthorized decryption of encrypted data and compromise the confidentiality of sensitive information.