CVE-2020-5523
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 · uneditedAndroid App 'MyPallete' and some of the Android banking applications based on 'MyPallete' do not verify X.509 certificates from servers, and also do not properly validate certificates with host-mismatch, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.
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 confidenceThe Android app 'MyPallete' and banking apps built on it fail to perform X.509 certificate chain verification and do not validate hostname matching, allowing MITM attackers to present fraudulent certificates and intercept sensitive data transmitted between the app and legitimate servers.
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<= 2.0.1<= 1.0.4<= 3.0.1<= 2.0.1<= 1.0.1all versions<= 2.0.1<= 3.0.4CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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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Identify installed banking appsOn Android devices, check installed applications for any of these: 77 Bank, Ashigin, Dogin, Hokuriku Bank Portal, Nagagin, MyPallete, Shikoku Bank, or Ikeda Senshu BankAffected if Any of these specific banking apps are installed on the device
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Check app versionFor each identified banking app, view its version in Android Settings > Apps > [App Name] > Version, or use adb shell dumpsys package [package name]Affected if The installed version matches or is below: 77 Bank <= 2.0.1, Ashigin <= 1.0.4, Dogin <= 3.0.1, Hokuriku Bank Portal <= 2.0.1, Nagagin <= 1.0.1, MyPallete (any version), Shikoku Bank <= 2.0.1, Ikeda Senshu Bank <= 3.0.4
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Review network security configFor developers: decompile the APK and examine res/xml/network_security_config.xml for certificate validation settings, or inspect the manifest for custom TrustManager implementationsAffected if Network security config lacks proper certificate validation settings, or custom TrustManager implementations exist that bypass standard validation
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Inspect SSL/TLS implementationFor developers: analyze the source code (Java/Kotlin) for HTTP client initialization (HttpURLConnection, OkHttp, Apache HttpClient) to verify that a proper TrustManager validating certificate chain and hostname is configuredAffected if The app uses a TrustManager that does not verify the full certificate chain, or hostname verification is disabled or missing
A user is affected if they have any of the listed banking apps installed with a version within the affected ranges, or if code review reveals missing certificate chain and hostname validation in the app's SSL/TLS implementation.
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 dataImplement proper SSL/TLS certificate validation in the Android app by using a correctly configured TrustManager that verifies the full certificate chain and validates that the certificate hostname matches the expected server, or implement certificate pinning for banking applications.
- Consultation4.0 h
- Implementation12.0 h
- Testing6.0 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 $7,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5523 — 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-2020-5523 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