Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 20 Jul 2023.
AndroidOperating system · Samsung

CVE-2021-25487

HIGH · 7.8 CVSS v3.1 Published 2021-10-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
96/100
Remediation priority · Urgent
In the wild 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
Lack of boundary checking of a buffer in set_skb_priv() of modem interface driver prior to SMR Oct-2021 Release 1 allows OOB read and it results in arbitrary code execution by dereference of invalid function pointer.

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

Out-of-bounds read vulnerability in the set_skb_priv() function of Samsung's modem interface driver due to missing boundary checks when handling a buffer. The OOB read can be leveraged to dereference an invalid function pointer, leading to arbitrary code execution.

MitigationApply Samsung's SMR Oct-2021 Release 1 or later security patch which adds proper boundary validation in the modem interface driver to prevent the OOB read condition.

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:= 8.1= 9.0= 10.0= 11.0

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

CVSS:3.1/AV:L/AC:L/PR:L/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. Identify the Android version
    Check the device settings under 'About Phone' > 'Android version' or run 'getprop ro.build.version.release' in ADB shell
    Affected if The version is 8.1, 9.0, 10.0, or 11.0
  2. Confirm the device is a Samsung device
    Verify the manufacturer is Samsung by checking 'About Phone' > 'Manufacturer' or running 'getprop ro.product.manufacturer' in ADB shell
    Affected if The manufacturer is Samsung (the vulnerability is specific to Samsung Android devices)
  3. Check the Samsung Maintenance Release (SMR) patch level
    Run 'getprop ro.build.version.sem' or 'getprop ro.vendor.build.security_patch' in ADB shell to obtain the SMR date
    Affected if The SMR date is earlier than October 2021 (SMR Oct-2021 Release 1 or later contains the fix)
  4. Verify the modem interface driver is present
    Check for the presence of the modem interface driver module by examining /proc/modules or running 'lsmod' in ADB shell for network/communication driver modules
    Affected if The device uses a modem interface driver with the vulnerable set_skb_priv() function (typical in Samsung devices with cellular connectivity)

A Samsung Android device running version 8.1, 9.0, 10.0, or 11.0 with an SMR patch level earlier than Oct-2021 Release 1 is affected by this vulnerability.

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 Samsung's SMR Oct-2021 Release 1 or later security patch which adds proper boundary validation in the modem interface driver to prevent the OOB read condition.

Recommended fix High confidence

Samsung SMR Oct-2021 Release 1 or later

  1. 1. Go to Settings on your Samsung Android device
  2. 2. Navigate to Settings > Software update (or Settings > System > Software update on some devices)
  3. 3. Tap on 'Download and install' to check for available updates
  4. 4. If the October 2021 SMR (SMR-OCT-2021) or later update is available, download and install it
  5. 5. After installation, verify the patch level in Settings > About phone > Software information matches October 2021 or later

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

Fix this in Android Exploited in the wild — priority engagement
  • Consultation6.0 h
  • Implementation8.0 h
  • Testing16.0 h
  • Review / QA6.0 h
36.0 hours of engineering $6,120
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,792.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-25487 — 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-2021-25487 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