App LoungeApplication · E.foundation

CVE-2021-43171

MEDIUM · 6.5 CVSS v3.1 Published 2023-08-22
Fix available
A fix is available. Upgrade to 0.19q or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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 · unedited
Improper verification of applications' cryptographic signatures in the /e/OS app store client App Lounge before 0.19q allows attackers in control of the application server to install malicious applications on user's systems by altering the server's API response.

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 confidence

The /e/OS App Lounge app store client before version 0.19q fails to properly verify cryptographic signatures of applications, allowing an attacker who controls the application server to inject malicious applications by altering the API response.

MitigationUpdate App Lounge to version 0.19q or later, which contains proper cryptographic signature verification for installed applications.

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
App LoungeApplication
Affected:< 0.19q

CVSS 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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Locate App Lounge on the device
    Open Settings > Apps > App Lounge, or use adb shell pm list packages | grep 'app lounge' to find the package, then check its version via adb shell dumpsys package foundation.e.app.lounge | grep versionName
    Affected if App Lounge is installed on the device
  2. Determine installed version
    Read the version number displayed in the app's Settings > About section, or from the adb command output in step 1
    Affected if The version displayed is any version number less than 0.19q (such as 0.19p, 0.19o, or earlier)
  3. Confirm vulnerability scope
    The vulnerability exists in all versions prior to 0.19q regardless of configuration. The flaw is in the signature verification logic itself, not an optional feature.
    Affected if The installed version is 0.19q or later - the issue only affects versions before 0.19q

If App Lounge is installed and its version is any build earlier than 0.19q, the device is affected by CVE-2021-43171.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

dbcve · scoped
Upgrade available Upgrade to 0.19q or later
Fixed in 0.19q
Interim mitigation

Update App Lounge to version 0.19q or later, which contains proper cryptographic signature verification for installed applications.

Recommended fix High confidence

App Lounge version 0.19q

  1. Open the Settings application on the /e/OS device
  2. Navigate to System > About Phone > Software Update (or similar path depending on /e/OS version)
  3. Check for and install any available system updates
  4. Alternatively, download and reinstall App Lounge version 0.19q or later from the official /e/OS repository or F-Droid

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in App Lounge Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-43171 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-43171 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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