Weak Key Derivation (no/low PBKDF2 iterations)

← Insufficient Cryptography

weak_key_derivation   MEDIUM

CategoryInsufficient Cryptography
OWASP Mobile (2024)M10
MASVSMASVS-CRYPTO-1
MASWEMASWE-0014
CWECWE-916CWE-327
PlatformAndroidiOS

Description

Derives keys from passwords with missing or trivial KDF iteration counts.

How it works

The encryption key is derived from the password with PBKDF2 at only a single iteration and a fixed, shared salt, orders of magnitude below OWASP guidance, so a cracking tool such as hashcat recovers it near-instantly. A second path skips the KDF entirely and uses raw SHA-256 of the password.

How to exercise it. DVMA is the harness - open this module from the home index and tap the demo action. The screen ships the malicious input and simulates the attacker (e.g. the companion app, crafted intent, or scanned payload) in-process, and the evidence panel prints the proof. The Tools (optional) and Attack inputs below are only needed to reproduce the exploit end-to-end on a real device.

Exploit steps

  1. Set up. Build DVMA with a flavor that enables the Insufficient Cryptography category (e.g. --dart-define-from-file=config/flavors/dev.json) and run on an emulator/simulator you control. The demo needs no external tooling; for the optional on-device reproduction the relevant tools are: hashcat, frida, frida-trace.
  2. Locate the target. From the home index, open Weak Key Derivation (no/low PBKDF2 iterations) (weak_key_derivation). The How it works section above describes this module’s specific weakness; the screen states the intended-secure behavior and exposes the vulnerable action.
  3. Exploit. Capture the algorithm/key/IV the module uses (the evidence panel prints it), then reproduce the weakness offline - e.g. recompute the digest, brute the short key, or decrypt a captured blob - to show the protection is ineffective.
  4. Observe the evidence. Trigger the vulnerable action and read the evidence panel - it prints the concrete proof (leaked value, accepted replay, executed payload, or unauthorized result).
  5. Contrast with the secure path. Run the module’s secure/hardened action (where provided) and confirm the same attack is rejected - this is what a correct implementation should do.

Tools (optional)