dbcve.org
AndroidOperating system · Google

CVE-2023-20664

MEDIUM · 6.7 CVSS v3.1 Published 2023-04-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
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
In gz, there is a possible double free due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS07505952; Issue ID: ALPS07505952.

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

A double free vulnerability exists in the gz (gzip) component due to a use-after-free condition. This memory corruption flaw allows local privilege escalation from System execution privileges, requiring no user interaction to exploit.

MitigationApply the vendor security patch ALPS07505952 through Android/system updates; verify patch level via system security settings.

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
AndroidOperating system
Affected:= 10.0= 11.0= 12.0= 13.0

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
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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. Check Android OS version
    Go to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADB shell
    Affected if Version is 10.0, 11.0, 12.0, or 13.0 (any minor version within these major releases)
  2. Verify security patch level
    Go to Settings > About Phone > Security patch level, or run 'getprop ro.build.version.security_patch' via ADB shell
    Affected if Patch level is earlier than the date of ALPS07505952 (the vendor-specific fix date)
  3. Confirm gz component is present
    Verify the gzip/zlib library exists on the device: run 'ls -la /system/lib/libz.so' or check for gz-related binaries in /system/bin via ADB shell
    Affected if The gz (gzip) library component is present on the device (which is standard on affected Android versions)
  4. Check for System-level access
    Determine if the device has apps or processes running with System privileges, or if the attacker already has System-level access (required for exploitation). Run 'ps -A | grep system_server' via ADB shell to check for System-level services.
    Affected if Attacker already has System-level execution privileges on the device

Device is affected if running Android 10, 11, 12, or 13 AND the security patch level is earlier than the vendor fix ALPS07505952, with System-level privileges present on the device.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor security patch ALPS07505952 through Android/system updates; verify patch level via system security settings.

Recommended fix Moderate confidence

Android Security Patch Level containing ALPS07505952 (typically the January 2023 or subsequent Android security update)

  1. 1. Identify the device model and ensure it uses a MediaTek chipset affected by this vulnerability
  2. 2. Check for available system updates from the device manufacturer
  3. 3. Apply the latest Android Security Patch Level update, which should include the fix for ALPS07505952
  4. 4. Verify the patch has been applied by checking Settings > About Phone > Security Patch Level
  5. 5. Alternatively, obtain a firmware update directly from the device OEM that incorporates the MediaTek ALPS07505952 patch
Caveat Ensure device has sufficient battery before updating; backup important data as a precaution

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

Fix this in Android Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing4.0 h
  • Review / QA3.0 h
10.0 hours of engineering $1,720
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Scan for this in your stack

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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-2023-20664 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