dbcve.org
AndroidOperating system · Google

CVE-2023-21079

MEDIUM · 6.7 CVSS v3.1 Published 2023-03-24
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 rtt_unpack_xtlv_cbfn of dhd_rtt.c, there is a possible out of bounds write due to a heap buffer overflow. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-254839721References: N/A

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

Heap buffer overflow vulnerability in the Wi-Fi RTT (Round-Trip Time) driver (dhd_rtt.c) where the rtt_unpack_xtlv_cbfn function does not properly validate buffer boundaries when processing XTLV data, leading to an out-of-bounds write. This allows local privilege escalation to System level from an already privileged position.

MitigationApply vendor-supplied Android kernel security patches; this requires updating the Wi-Fi driver (dhd_rtt.c) with proper bounds checking on XTLV data parsing to prevent heap overflow.

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:all versions

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. Verify Wi-Fi RTT feature is in use
    Check if the device uses Wi-Fi RTT (802.11mc) by examining kernel config for CONFIG_WLAN_FEATURE_RTT or reviewing active Wi-Fi interfaces with RTT capability. On Android, this can be checked via 'settings get global wifi_rtt_available' or by inspecting kernel modules loaded for the Wi-Fi driver.
    Affected if Wi-Fi RTT (802.11mc) is enabled and the device has a Broadcom or similar Wi-Fi chipset using the dhd driver.
  2. Identify the Wi-Fi driver in use
    Check which Wi-Fi driver is loaded: 'ls -la /sys/module/' and look for 'dhd' or 'bcmdhd' modules. The vulnerability exists in dhd_rtt.c which is part of the Broadcom/Horus dhd driver.
    Affected if The system uses the dhd (Broadcom/Horus) Wi-Fi driver.
  3. Check kernel source for vulnerable function
    Examine the file dhd_rtt.c in the kernel source or /system/vendor/firmware/ for the rtt_unpack_xtlv_cbfn function. Look for the specific XTLV parsing code that lacks boundary validation before the out-of-bounds write.
    Affected if The function rtt_unpack_xtlv_cbfn processes XTLV data without proper bounds checking before copying data to the heap buffer.
  4. Verify patch status
    Check the Android security patch level: 'settings get security patch level' or examine /system/build.prop for 'ro.build.version.security_patch'. Compare this to the month when CVE-2023-21079 was addressed in the Android security bulletin.
    Affected if The device security patch level predates the CVE-2023-21079 patch release date.

A device is affected if it runs Android with the dhd Wi-Fi driver, has Wi-Fi RTT enabled, and lacks the vendor security update that patched the bounds-checking flaw in rtt_unpack_xtlv_cbfn.

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 vendor-supplied Android kernel security patches; this requires updating the Wi-Fi driver (dhd_rtt.c) with proper bounds checking on XTLV data parsing to prevent heap overflow.

Recommended fix Moderate confidence

Latest Android system update containing the Android Security Patch Level for CVE-2023-21079 (Android ID A-254839721)

  1. 1. Navigate to Settings > System > System Update on the Android device
  2. 2. Check for and install any available Android system updates
  3. 3. Ensure the device is updated to a version that includes the Android Security Patch Level addressing A-254839721
  4. 4. After update installation, verify the patch level by going to Settings > About Phone > Android Version or Settings > System > Security > Security Patch Level
  5. 5. Confirm the security patch level is the one that includes the fix for CVE-2023-21079
Caveat Standard Android upgrade considerations apply - ensure app compatibility and backup data before updating

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

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-21079 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2023-21079 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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