CVE-2020-36285
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUnion Pay up to 3.3.12, for iOS mobile apps, contains a CWE-347: Improper Verification of Cryptographic Signature vulnerability, allows attackers to shop for free in merchants' websites and mobile apps, via a crafted authentication code (MAC) which is generated based on a secret key which is NULL.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceUnion Pay iOS mobile apps up to version 3.3.12 have improper cryptographic signature verification (CWE-347). The vulnerability stems from a NULL secret key being used to generate MAC (Message Authentication Code) values for transaction authentication. Attackers can craft valid authentication codes without knowing the actual secret key, allowing fraudulent free purchases.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 3.3.12CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify Union Pay iOS app is installedCheck your iOS device for the Union Pay mobile app (named 'UnionPay' or 'Unionpayintl') in the app list or Settings > General > iPhone StorageAffected if The app is present on the device
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Identify the installed app versionOpen the App Store, go to your account profile, find 'Purchased' apps, locate Union Pay, and view the version number. Alternatively, check in the app's 'About' or 'Settings' section if availableAffected if The displayed version is 3.3.12 or any version number lower than 3.3.12
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Confirm transaction authentication usageDetermine if the app is used or configured for payment transactions, card management, or financial operations that require MAC (Message Authentication Code) generationAffected if The app processes or has processed financial transactions requiring authentication
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Check for NULL key vulnerability indicatorIf you have access to app logs or network traffic analysis, look for any authentication requests that succeed without proper key verification or display cryptographic errors related to secret key initializationAffected if Transactions authenticate successfully despite missing or uninitialized secret key configuration
You are affected if the Union Pay iOS app version 3.3.12 or lower is installed and is used for transaction processing that relies on MAC-based authentication.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate Union Pay iOS mobile apps to a version beyond 3.3.12. Implement proper secret key management and ensure cryptographic signature verification validates against a correctly provisioned, non-null secret key.
- Consultation4.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,960.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-36285 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-36285 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data