M6: Broken Cryptography
Learn about the impact of Broken Cryptography in mobile apps and methods to prevent unauthorized retrieval of sensitive information. Follow encryption best practices.
Overview
Broken Cryptography refers to the vulnerability that occurs 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
Broken Cryptography is a common threat in mobile apps that leverage encryption. There are two primary ways in which this vulnerability can occur. Firstly, the encryption/decryption process implemented in the mobile app may be fundamentally flawed and can be exploited by an adversary to 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 reputation of the business.
How to Prevent ?
To prevent Broken Cryptography, it is important to follow best practices for encryption. This includes using modern and strong encryption algorithms accepted by the security community. Additionally, proper key management processes should be implemented to ensure that the keys are not accessible to attackers. It is crucial to avoid using hardcoded keys within the binary and to 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 Broken 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 Broken 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.