MASA or a mobile penetration test: which one your app needs
An app that handles sensitive data or talks to a backend API usually needs a scoped mobile penetration test, and a MASA review alone is rarely enough. MASA is a lab validation of the app against MASVS Level 1 requirements, using the MASTG, with the independent review shown in the Data safety section of the Google Play listing. That makes it a useful baseline signal for a listing, but the App Defense Alliance states that MASA reviews are limited in nature and do not guarantee complete safety. Developers also remain responsible for accurate Data safety declarations, so a badge does not replace them.
MASA fits when the app is a lower-risk consumer product, the team needs a documented Level 1 baseline before release, and the main question is whether the basic storage, crypto, authentication, network, platform, code and privacy requirements are met. A scoped penetration test fits when the app stores or processes sensitive data, depends on backend APIs where broken object level authorization or broken authentication could expose other users' records, or needs resilience against reverse engineering and tampering. OWASP's MAS project defines L2 for apps handling sensitive data and R for resilience, and these profiles go beyond Level 1. Ask the test provider which profile and which backend endpoints are in scope, and confirm that the written scope covers both the client and the server side.
Many regulated teams combine the two: MASA for the listing signal and a penetration test for depth. Confirm with the lab and the tester which findings are shared, who fixes them, and how the retest is recorded, because a MASA result does not cover the backend. Ask for the tester's rules of engagement and a clear statement of what the test did not cover, since that gap is where the residual risk sits.
How MASA and a mobile penetration test compare on scope, method and output
This table compares what a MASA lab validation and a scoped mobile penetration test each set out to show, who does the work, and what the buyer can see. Read it to decide whether the listing badge answers your question or whether you need tester-led depth on the app and its backend.
| Dimension | MASA (App Defense Alliance) | Scoped mobile penetration test |
|---|---|---|
| Primary goal | Show that an authorized lab has validated the app against MASVS Level 1 requirements | Find exploitable weaknesses in the app, its data handling and its backend, and show how they could be used |
| Who performs the work | An authorized MASA lab partner, using the MASTG as its test method | Your chosen tester or firm, under a written rules of engagement and statement of work |
| Standard applied | MASVS Level 1 requirements, tested with the MASTG | Scope agreed in advance, often mapped to MASVS and MASTG profiles (L1, L2, R) plus API testing guidance for the backend |
| Backend and API coverage | Not described in the supplied MASA material. Confirm with the lab whether server-side APIs are in scope | Can include the backend APIs, authentication and object-level authorization if written into scope. Confirm with the tester |
| Testing profiles | Level 1 only. L2 and R are not part of this validation as described | Profile is a scoping choice: L1 for basic requirements, L2 for apps handling sensitive data, R for reverse engineering and tampering resistance |
| What the buyer sees publicly | A MASA review indicator in the Data safety section of the Google Play listing | Private report to the client. Public disclosure is the client's decision, and no listing badge is implied |
| Depth and time bounds | Described by the App Defense Alliance as limited in nature, with no guarantee of complete safety. Effort and duration are not supplied here | Set by the agreed scope, test hours and environments. Ask the tester for the planned days, the environments tested and what is excluded |
| Developer responsibility | Developers remain responsible for accurate Data safety declarations, whether or not a MASA review exists | Developers remain responsible for fixes, retesting and keeping Data safety declarations accurate |
| Key question to confirm | Which app version and build the lab reviewed, and how long the result remains current after updates | Whether the tester will test authenticated flows, backend APIs and the release build, and what retest is included |
What each approach finds and what it misses
A MASA review checks an app against MASVS Level 1 controls in a lab, while a scoped penetration test follows the app's behavior and its backend wherever it leads. The cards below show where each approach reaches, where it stops, and the conditions under which the gap matters.
MASVS controls a Level 1 review checks
A MASA validation tests Level 1 requirements from the MASVS control groups: storage, cryptography, authentication, network, platform, code and privacy. These checks cover the app's local behavior, such as how it stores data, handles keys, uses TLS and requests permissions. For a consumer app with modest data, this is a useful baseline. Check whether the lab's scope names the MASVS version and whether the Data safety declaration matches what the app actually collects.
Resilience against reverse engineering
Profile R in the OWASP MAS testing profiles covers resilience against reverse engineering and tampering, such as code obfuscation, root and debugging detection, and integrity checks. A Level 1 review is not built to judge these defenses. This gap matters for apps that hold payment credentials, digital keys or licensed content, where an attacker with a rooted device could clone or modify the client. Ask whether the assessment includes profile R or whether it is excluded from scope.
Backend authorization flaws
Mobile backends are usually APIs, and the OWASP API Security Top 10 2023 ranks Broken Object Level Authorization (API1) first, followed by Broken Authentication (API2). A client-side review cannot show that the server checks whether user A may read user B's record by changing an object ID. A penetration test that includes the backend, with two test accounts, can probe these flaws directly. This matters most when the app returns customer, health or financial records.
Business logic and misconfigurations
A tester can chain steps that a fixed checklist does not model, such as skipping a payment confirmation, reusing a one-time code, or reaching a premium feature through an unprotected endpoint. Misconfigured cloud storage, debug endpoints left in release builds and overly broad API responses also surface in manual testing. These issues matter when the app's value depends on workflow rules rather than on input handling. Ask the tester to document the workflows in scope and the accounts and roles used.
Blind spots of each approach
A MASA review does not test the backend, does not test resilience, and is described by the App Defense Alliance as limited in nature, with no guarantee of complete safety. A penetration test depends on scope, timing and tester skill, and it gives a point-in-time view. If the app is a thin client over a shared API used by other channels, a MASA badge covers the client alone. Confirm in writing which MASVS version, profile and backend hosts each option covers before you treat either as complete.
Why a lab review and a penetration test answer different questions
A MASA review and a mobile penetration test answer different questions, and a buyer who treats one as a substitute for the other will end up with a gap. MASA asks whether the app meets a defined baseline. Google's Mobile Application Security Assessment is run through the App Defense Alliance, where authorized lab partners validate the app against the MASVS Level 1 requirements using the MASTG. The check is structured around those requirements, so the lab works through a fixed set of controls on the client: how data is stored, how cryptography and authentication are implemented, how network traffic is protected, and how the app handles platform features and privacy. The result is shown in the Data safety section of the Google Play listing. The App Defense Alliance is explicit that these reviews are limited in nature and do not guarantee complete safety, and that developers remain responsible for accurate Data safety declarations.
A penetration test asks what an attacker could actually do with the app and its backend. It starts with a written rules of engagement, the approach NIST SP 800-115 describes for review and testing work, where the scope, permitted techniques, testing windows and escalation contacts are agreed before any attack traffic is sent. NIST SP 800-115 separates passive review techniques, which pose minimal risk, from penetration testing, which uses real exploits and carries high risk. For a mobile engagement, the tester usually covers the client and the API endpoints it calls, so authorization flaws such as broken object level access, which the OWASP API Security Top 10 2023 ranks first, are tested with real accounts and data. Confirm with any provider whether the backend is in scope, which test accounts they will receive, and whether testing runs against production or staging.
The OWASP WSTG makes the broader point that no single technique is enough, and that a mix weighted toward early development phases gives better coverage. Treat a MASA review as one input that confirms the client-side baseline, and a scoped penetration test as the input that examines the attack paths that baseline cannot see. Apps that handle sensitive data, or that depend on an API for authorization decisions, usually need both, sequenced so the penetration test can focus on what the lab did not examine. Before you commit, confirm with the lab which MASVS version and testing profile its review covers, and confirm with the tester which findings, retesting and evidence the statement of work includes.
What you receive from a MASA review and from a penetration test
This table compares what each engagement hands you at the end, from the listing evidence a MASA review produces to the findings, rules of engagement and retest support a penetration test can include. Read the rows as questions to settle in writing before work starts, because the content of a report and who owns it depend on the contract.
| Deliverable | MASA review | Mobile app penetration test |
|---|---|---|
| Primary output | An independent review by an authorized lab against MASVS Level 1, shown in the Data safety section of the Google Play listing | A scoped written report of tested components, findings and evidence, delivered to the client |
| Who sees the result | Public listing signal for users, with the developer remaining responsible for accurate Data safety declarations | Client and named stakeholders only, unless the client chooses to share it |
| Level of detail | Pass-level validation against Level 1 requirements, not a list of individual defects for the developer to fix | Findings with severity, affected component and reproduction steps, depending on the agreed scope |
| Stated limits | The App Defense Alliance says MASA reviews are limited in nature and do not guarantee complete safety | Coverage is only what the rules of engagement and scope name, so untested backend endpoints or flows will not appear in the report |
| Rules of engagement | Set by the program, not negotiated per app | Written before testing: testing windows, permitted accounts, production or staging targets, data handling and escalation contacts |
| Retest and remediation | Not part of the listing review; a new review is needed to refresh the evidence | Confirm in the statement of work whether retest of fixed findings is included, how many rounds, and who verifies closure |
| Ownership and reuse | Ask the lab and program what evidence the developer keeps and how it can be cited | Confirm before work starts who owns the report, whether it can be shared with app stores or auditors, and how raw evidence is retained or destroyed |
How to decide the sequence when an app needs both
This sequence helps a team decide whether the MASA listing badge, a scoped mobile penetration test, or both answer its risk and compliance needs, and in what order to act. The output is a documented scope that names the data, profile, backend and retest plan before any engagement is bought.
Confirm the data the app handles
The product owner, privacy lead and security lead list the personal, financial, health or other sensitive data the app stores, transmits or caches on the device, and note which data is declared in the Data safety section of the Google Play listing. This step is done when the team has a written data inventory that the buyer's own risk assessment and compliance obligations can be measured against. Sensitivity drives everything after it, so record any regulatory duty the data triggers and confirm it with counsel or the compliance owner.
Choose the MASVS profile that fits
Using the data inventory, the security lead selects the OWASP MAS testing profile: L1 for basic security requirements, L2 for advanced security in apps handling sensitive data, or R where resistance to reverse engineering and tampering matters. The output is a one-line profile decision with its reason, signed off by the risk owner. Note that MASA validates against MASVS Level 1 only, so an app that needs L2 or R will need a penetration test or other assessment scoped to that profile.
Map the backend APIs the app calls
The engineering lead produces a list of every backend endpoint, third-party service and authentication flow the app uses, including the hosts it reaches and the roles that access them. Mobile backends are usually APIs, so this list is the basis for testing object-level and authentication controls, which the OWASP API Security Top 10 2023 ranks first and second. The step is complete when the list is reviewed against the source code or API documentation and any gaps are logged as open items.
Test whether the listing badge answers the need
The compliance lead and the business owner compare the stakeholder requirement with what the MASA review covers and does not cover. The App Defense Alliance states that MASA reviews are limited and do not guarantee complete safety, and that developers remain responsible for accurate Data safety declarations. If a stakeholder needs assurance over the backend, server-side logic or the L2 or R controls, the badge alone will not meet it. The output is a written decision: badge only, penetration test only, or both, with the reason recorded.
Scope the penetration test to app and backend
The security lead and the testing provider agree a written scope that names the app builds, platforms, environments, the API endpoints from the map, the test accounts and roles, and the MASVS profile. Ask the provider to state how the client and backend are each covered and what is excluded. The step closes when rules of engagement and the scope document are signed, which matches the approach NIST SP 800-115 describes for agreeing targets and limits before testing begins.
Run the MASA review and the scoped test
Where the decision includes the badge, the developer submits the app through the App Defense Alliance process with an authorized lab partner, while the testing provider works against the agreed scope. Each result is kept separately so the badge outcome does not stand in for backend findings. The step is complete when both reports are on file and the team can show which findings came from the lab review and which from the penetration test. Confirm current submission steps directly with the App Defense Alliance.
Fix findings and confirm the fixes
The development team triages findings by severity and data exposure, fixes them in the app and backend, and records the change against each finding. The security lead then checks that each fix resolves the issue, and updates the Data safety declaration if behavior changed. The output is a closed findings register with evidence for every item that is marked resolved.
Schedule retesting after each release
The security lead sets a retest plan tied to new releases, backend changes and the review cycle set by the buyer's risk assessment, rather than assuming a single assessment stays valid. Retests cover changed endpoints and any findings that were fixed, and the team confirms the MASVS profile still matches the data. The step is complete when the cadence is written into the release process and the owner is named. Ask any provider to quote retesting as a separate line item in the written scope.
What drives cost and effort on each side
A MASA review and a scoped mobile penetration test are bought in different ways and recur differently. The cards below cover what each side is paid for, what the developer must prepare, and what to request in writing before comparing quotes.
Who is paid for a MASA review
A MASA review is validated by an authorized lab partner of the App Defense Alliance, and the developer contracts with that lab for the MASVS Level 1 validation against the MASTG. The fee and scope are set by the lab, not by the app's backend or the number of features. Ask the lab which MASVS Level 1 requirements it covers, whether it tests the app binary only, and whether the result is tied to a specific build. Check the ADA page for the current process before you budget.
Developer preparation for a review
The developer owns the work that makes a review possible: a buildable test version, accurate test accounts, documentation of data flows, and an honest Data safety declaration in the Google Play listing. The App Defense Alliance states that developers remain responsible for those declarations. Ask the lab what build, credentials and documentation it needs, and who on your team answers questions during the review.
Scope of app versus backend
A MASA review validates the client app against Level 1 requirements, while a mobile penetration test can also cover the APIs the app calls. Mobile backends are usually APIs, so an app-only quote leaves the server-side authorization and authentication logic untested. Ask each vendor to state in writing whether the backend endpoints, admin interfaces and third-party services are in scope, and who owns the test accounts for each tenant or role.
Platforms, authentication flows and profile
Effort rises with each platform (Android, iOS or both), each distinct login path such as SSO, biometric unlock or passwordless recovery, and each testing profile. OWASP MAS defines L1 for basic security, L2 for apps handling sensitive data and R for resilience against reverse engineering and tampering. Ask the tester which profile the quote assumes and whether resilience testing is included or priced separately.
Depth, access and report needs
A penetration test is priced by the depth of manual exploitation, the access provided (black box, grey box with user accounts, or source code review) and the report format your auditors expect. Requests for a technical appendix, executive summary or evidence for a regulator add review time. Ask what access the tester needs, whether source code or documentation is part of the work, and what the report must contain to satisfy your compliance team.
One-time work versus recurring retests
The initial assessment is one-time work, but each new release that changes the client, authentication or data handling can trigger another review or a retest. A MASA listing is tied to the independent review you obtained, so a major change may require new validation. A penetration test quote should state whether retesting of fixed findings is included, how many rounds are allowed and how long after the report the retest window stays open.
Questions buyers ask before choosing MASA or a mobile penetration test
Does a MASA review replace a mobile penetration test?
No, not in most cases. MASA is a lab validation of an app against MASVS Level 1 requirements using the MASTG, and the App Defense Alliance states that MASA reviews are limited in nature and do not guarantee complete safety. A scoped penetration test is an exception-based, tester-led attack on the app and, where in scope, its backend, so it can find logic flaws and chained weaknesses that a requirements checklist may not reach. The two answer different questions, and many teams treat MASA as a baseline signal and a penetration test as depth. Confirm with the lab and your tester which MASVS levels and testing profiles each one covers before you rely on either for a specific risk.
What does the development team need to provide for a mobile assessment?
The work needs stable builds, access and documentation, and the team's time to answer questions. For a MASA-style review, expect to supply a build the lab can test and to keep your Google Play Data safety declarations accurate, because the App Defense Alliance makes developers responsible for those. For a penetration test, the scope usually also needs:
- Test builds for the platforms in scope, with debug or test flags agreed in advance
- Test accounts at each privilege level and a description of the roles
- API documentation, environment URLs and any rate limits or IP allowlisting
- A named contact who can respond during testing
Ask the tester which of these are required for your app, and whether source code access is needed for the level you want.
How long does each option take?
No duration is supplied for either option here, so confirm it for your app. The effort depends on the number of screens and features, the platforms covered (Android, iOS or both), how many MASVS requirements or OWASP MAS testing profiles apply (L1, L2 or R), the size of the backend and how quickly the team answers questions. Ask the lab for its expected process and turnaround for MASA validation, and ask a penetration tester for a written schedule tied to the agreed scope. Fixed-scope engagements agree deliverables and timelines in writing before work starts.
Can an in-house team run a MASA-style check itself?
An in-house team can check its app against MASVS requirements and the MASTG, but a MASA review is performed by an authorized lab partner, and its result is what appears in the Google Play listing. Your own team can run internal checks at the same control groups, such as storage, authentication, network and privacy, to catch problems early. Be clear about what that proves: internal checks do not produce the independent review that the listing shows. For independent depth, a qualified tester is still needed, and you should confirm the tester's methods and reporting before purchase.
What does the Google Play listing badge prove and what does it not prove?
The badge shows that an authorized lab validated the app against MASVS Level 1 requirements and that developers can show the independent review in the Data safety section. It does not prove the app is secure, that every risk was tested, or that the Data safety declarations are correct. The App Defense Alliance states that reviews are limited and that developers remain responsible for accuracy. It also does not cover a backend unless that backend was in the validated scope, and it does not replace a penetration test for apps that handle sensitive data. Read the scope the lab used before you describe the badge to customers or auditors.
How does the backend change the scope?
Mobile backends are usually APIs, so a client-only review can leave the server-side authorization and authentication controls untested. The OWASP API Security Top 10 2023 ranks Broken Object Level Authorization first (API1) and Broken Authentication second (API2), and both are commonly reached through an app's API calls. Decide early whether the backend is in scope for the MASA-style review, which typically covers the app itself, and whether your penetration test includes the API endpoints. Many teams scope one engagement for the app and another for the API, or a combined one with a clear list of endpoints, roles and environments. Confirm the scope with the tester in writing.
What does a retest after fixes involve?
A retest checks whether reported issues were fixed and whether the fix introduced new exposure in the same area. It usually repeats the original test steps for each finding, using a build that contains the fix, and it records the result for each item. For a MASA-style validation, a re-review depends on the lab's process, so ask whether resubmission is covered and what it costs. For a penetration test, agree in the statement of work whether retests are included, how many rounds apply, which build is tested and how long the retest window is. Retesting is often billed separately from the original test, so request that split in the quote.
When a compliance framework or customer asks for each
Start by reading the request literally. A framework or customer that asks for a penetration test is asking for a human-led attack against the target, not a scan. CIS Controls v8.1 Safeguards 18.2 and 18.5 ask for external and internal penetration tests at least annually, and PCI SSC's Penetration Testing Guidance states that simply running an automated tool does not satisfy the penetration testing requirement. A MASA listing cannot stand in for that request. The MASA review validates an app against MASVS Level 1 requirements in a lab, and the App Defense Alliance states that such reviews are limited in nature and do not guarantee complete safety. Confirm with your assessor or customer which control or clause they are mapping to before you offer MASA as evidence.
DORA Article 25(1) lists penetration testing alongside vulnerability assessments, scenario-based tests and open source analyses, so a financial entity may need a penetration test as one element of its digital operational resilience testing programme. NIST SP 800-115 says organizations often combine techniques to reach an in-depth assessment at an acceptable level of risk, which is a useful argument for pairing a MASA lab validation with a scoped penetration test of the app and its backend. The MASA result covers a defined Level 1 baseline on the client, while the penetration test covers the authorization and session behavior of the API that the app calls. Ask your regulator or auditor whether they accept a combined approach, and record which techniques were used and why.
MASA is a Google Play listing signal, not a compliance attestation, and DeployOpen does not issue audit reports, attestations or certifications. Where a framework requires an independent certificate or regulator-recognized report, the issuing body must provide it. DeployOpen can plan the scope, run the penetration test, prepare the evidence and document how the MASA review and test results map to the requirement, and independent auditors or certification bodies make the determination. Before you commit, ask the assessor which evidence format they will accept and whether a listing badge, a lab report or a tester's report is the document they need.
How DeployOpen works on this
DeployOpen runs mobile security testing inside the client's own infrastructure and tooling, and sets the boundary between a MASA-style lab validation and a scoped penetration test in writing before work starts. Engagements are fixed-scope, with deliverables and timelines agreed up front, and ongoing support is available as a retainer.
How we scope
- The written scope names the app builds, platforms, user roles and backend APIs that are in and out of the test.
- We record whether the goal is a Google Play MASA review, a penetration test, or both, and what each must prove.
- The scope states which MASVS and MAS testing profiles apply, such as L1, L2 or R, and why each was chosen.
- Rules of engagement cover test accounts, test data, permitted hours and how production data is handled.
How we build
- We set up the test environment, including a staging backend, test accounts and instrumented devices, before testing starts.
- Testing covers client storage, cryptography, authentication, network, platform and code behavior against the agreed profile.
- Backend API testing checks object-level and function-level authorization, authentication and data exposure in each endpoint.
- Findings are validated by hand, so each one carries reproduction steps, affected versions and a severity rationale.
How we hand over
- The report lists scope, method, tools, coverage gaps and each finding with evidence and a remediation path.
- A retest of fixed issues is included in the written scope, with its boundaries and deadlines agreed in advance.
- We prepare evidence for your Data safety declaration review, but the declaration remains the developer's responsibility.
- Handover includes a short session with developers and security staff to walk through findings and fixes.
How we support
- Ongoing support is available as a retainer for re-testing after each app release and for new backend endpoints.
- Retainers can cover periodic re-testing as MASVS and MASTG guidance changes, with the cadence set in writing.
- We document test procedures so your team can repeat them, and advise on which checks to automate in pipelines.
- Clients should confirm with us which lab validation, audit or certification claims, if any, their evidence can support.
