Top Vulnerabilities in Mobile Applications and How to Avoid Them
Today’s theme: Top Vulnerabilities in Mobile Applications and How to Avoid Them. Welcome! We’ll turn scary security pitfalls into practical, confidence‑building steps you can use right away. Read, reflect, and join the discussion to strengthen your app.
A real‑world wake‑up call
A small fintech team shipped a beta with verbose logs enabled. A commuter found a lost phone, opened the app, and saw bearer tokens in plain text. No hack wizardry—just careless defaults. Share your own lessons so others avoid the same stumble.
OWASP Mobile Top 10 made practical
Lists are useful, but mapping them to your architecture is transformative. Tie each OWASP Mobile Top 10 item to your screens, API calls, storage layers, and release process, then prioritize by real user impact and data sensitivity. Comment if you want a checklist.
Risk‑first thinking beats checkbox security
Start with what an attacker wants: money, data, influence, or reputation. Trace how they might reach it through your app’s flows. You’ll uncover high‑value vulnerabilities faster than by blindly following tools. Subscribe for deeper threat‑modeling guides.
Insecure Data Storage: Secrets Spilled on the Device
Plaintext pitfalls and safer storage choices
Avoid storing tokens, secrets, or PII in plaintext files, SQLite, or SharedPreferences/UserDefaults. Prefer hardware‑backed Android Keystore or iOS Keychain, encrypt with AES‑GCM, use file protection classes, and exclude sensitive files from backups. Tell us your current setup to get tailored tips.
Leaky logs, screenshots, and caches
Redact tokens from logs, disable debug logging in production, and mask sensitive screens to prevent OS screenshots in app switchers. Periodically clear caches and consider encrypted in‑memory stores. Comment if your team uses a log redaction library and how it performs.
The stolen‑device scenario
Imagine a thief finds a phone with your app. If offline data reveals session tokens or personal records, damage follows. Require re‑authentication for sensitive actions and bind sessions to device posture. Share how you balance convenience with safety.
Authentication and Session Management: Keeping Identity Safe
Adopt OAuth 2.0 with PKCE and OpenID Connect where possible. Favor short‑lived access tokens, refresh tokens protected in the Keychain/Keystore, and rotate secrets regularly. Never hardcode client secrets in the app. Ask us for a sample threat model template.
Authentication and Session Management: Keeping Identity Safe
Expire tokens promptly, revoke on logout, and re‑authenticate for high‑risk actions like payments or profile changes. Consider device binding and step‑up auth after suspicious behavior. Do you enforce idle and absolute timeouts? Share what works for your users.
Secure Communication: Guarding Data in Transit
Enforce TLS 1.2+ and disable cleartext traffic with Android Network Security Config and iOS App Transport Security. Validate hostname properly and avoid custom, permissive trust managers. Comment if you need a quick audit script for your endpoints.
Secure Communication: Guarding Data in Transit
Implement certificate or public key pinning for critical flows, but plan for rotation using multiple pins and staged rollouts. Monitor for pinning failures to avoid bricking clients. Share whether you pin, and we’ll discuss safe rotation strategies.
Never trust client claims about ownership
Prevent IDOR by validating resource ownership on the server for every request. Do not rely on hidden fields, disabled buttons, or client‑side checks. Log denied attempts to spot probing patterns. Share an example endpoint and we’ll walk through safer checks.
Deep links, intents, and universal links done right
Validate parameters, verify signatures, and restrict which apps can handle your links. On Android, review intent filters; on iOS, enforce Associated Domains. A support ticket once revealed a link opening the wrong account screen—caught just in time. Tell us your testing approach.
Feature flags and premium gates
Do not rely on hidden UI or client‑side toggles to guard paid features. Enforce entitlements server‑side, and re‑check on critical actions. Audit endpoints for privilege escalation paths. How do you separate presentation from authorization? Share your pattern.
Use R8/ProGuard for Android, strip symbols on iOS, and remove debug strings. Keep mapping files secure. Obfuscation is not a shield, but it slows casual adversaries. Comment if you’ve balanced obfuscation with crash readability successfully.
Reverse Engineering and Tampering: What Attackers See
Cryptography: Strong by Design, Not by Hope
Generate keys with secure RNG, store them in hardware‑backed keystores or the Keychain, and rotate regularly. Prefer AES‑GCM for confidentiality and integrity; never use ECB. Document ownership and expiry policies. Ask for our rotation checklist if helpful.
Cryptography: Strong by Design, Not by Hope
Derive keys using PBKDF2, scrypt, or Argon2 with unique salts and strong iteration counts. Use CSPRNGs for IVs and nonces. Zero sensitive memory after use. How do you validate entropy in tests? Share your method to spark ideas.
Third‑Party SDKs and the Mobile Supply Chain
Audit SDK permissions and remove any your app does not truly need. Challenge vendors that request broad access. Keep a tight manifest and document why each capability is necessary. Share the trickiest permission you had to justify to stakeholders.
Third‑Party SDKs and the Mobile Supply Chain
Produce a Software Bill of Materials (CycloneDX or SPDX), track versions, and scan for CVEs with SCA tools. Establish an update cadence and test fallbacks. Do you automate dependency PRs? Tell us your workflow for timely, safe upgrades.