CVE-2021-25487 is an out-of-bounds read vulnerability in Samsung Mobile Devices. CISA added it to the Known Exploited Vulnerabilities catalogue on 29 June 2023, which means attackers have used it in real attacks. Organisations running the affected product should apply the vendor fix or mitigation as a priority.
What This Vulnerability Means on a Mobile Device
An out-of-bounds read in a mobile operating system or device component means the software can read memory beyond its intended boundary. On a smartphone, that can expose internal data, weaken isolation between processes, or provide the raw information an attacker needs to chain into a larger compromise.
For Samsung Mobile Devices, the practical concern is not just the memory bug itself, but the fact that it was added to the CISA Known Exploited Vulnerabilities catalogue on 29 June 2023, which signals real-world abuse and makes exposure a priority issue for defenders.
Why Out-of-Bounds Reads Are Dangerous
Out-of-bounds reads are often treated as a confidentiality problem, but on mobile devices they can also become a stepping stone to stability issues, sandbox escape attempts, or further exploitation. If the read leaks pointers, flags, object contents, or security-sensitive state, attackers may gain the visibility needed to tailor a second-stage exploit.
That matters especially in an ecosystem like mobile, where the device is both a personal endpoint and a trust anchor for email, messaging, MFA, corporate apps, and personal data. A successful read primitive can reveal more than one app’s data path if the vulnerable component sits close to shared system services.
How Organisations Check Exposure and Prioritise Response
Start with a clear inventory of Samsung devices, the Android or firmware versions they run, and which models are still in service. Then compare that inventory with the vendor advisory and the CISA KEV catalogue so you know whether the vulnerable component is present and whether the device is already in a known-exploited state.
The CVE Program provides the canonical identifier for the issue, while NIST National Vulnerability Database is the normal reference point for record details and downstream enrichment. For organisations running fleets of phones, Mobile Device Security Guide helps frame the device inventory and control plane around MDM, enrolment, and policy enforcement.
Remediation, Detection, and Aftercare
When a patch or vendor mitigation is available, treat it as a priority update and verify completion across managed and unmanaged devices. If immediate remediation is not possible, reduce exposure by restricting risky app installs, tightening mobile management policy, and limiting access to sensitive corporate resources from unpatched devices.
Detection should look for signs that a vulnerable device has already been targeted, not just whether the patch is present. Review crash logs, mobile telemetry, app anomalies, and any unusual access to accounts or data that the device could reach. If exploitation is suspected, a post-patch review should consider whether tokens, sessions, or other identity material on the device may need rotation.
Samsung-specific mobile risk is easier to manage when device hygiene and access control are treated together, because a compromised phone is often also a trusted authentication factor. If that trust is broken, the response has to extend beyond the operating system fix.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
CIS Controls v8, NIST SP 800-53 Rev 5 and NIST CSF 2.0 set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| CIS Controls v8 | CIS-7 — Continuous Vulnerability Management | Known-exploited mobile flaws require prompt identification and remediation. |
| Recommendation — Prioritise KEV-listed Samsung devices for patching and validate remediation completion. | ||
| NIST SP 800-53 Rev 5 | SI-2 — Flaw Remediation | The term concerns a known exploitable software flaw needing vendor remediation. |
| RA-5 — Vulnerability Monitoring and Scanning | Exposure must be confirmed through inventory and vulnerability monitoring. | |
| Recommendation — Apply vendor remediation quickly and track status until the flaw is corrected. Scan and inventory Samsung endpoints to confirm which devices remain exposed. | ||
| ISO/IEC 27001:2022 | A.8.8 — Management of technical vulnerabilities | This vulnerability requires technical vulnerability management and prioritisation. |
| Recommendation — Track the CVE through a formal vulnerability process and enforce remediation deadlines. | ||
| NIST CSF 2.0 | PR.IP-12 — Vulnerability management | The subject is a known exploited vulnerability that belongs in vulnerability management. |
| Recommendation — Use vulnerability management to triage, remediate, and verify affected devices. | ||
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Reviewed and updated by the NHIMG editorial team on October 17, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org