Security readout for executives and security teams
Plain-English summary
This is a critical Samsung Mobile media parsing flaw. A maliciously crafted media item could cause code execution inside Android's mediaextractor process on affected Samsung devices. The issue affects older Android generations before Samsung's May 2021 security maintenance release, so unmanaged or unsupported mobile fleets carry the main business risk.
Executive priority
Prioritize remediation for corporate Samsung mobile fleets, especially unmanaged or legacy devices. The vulnerability has critical impact potential, but available sources do not confirm exploitation. The practical executive action is rapid patch verification and removal of unsupported devices from sensitive access.
Technical view
CVE-2021-25386 is improper input validation in sdfffd_parse_chunk_FVER() within Samsung's libsdffextractor library. Sources map it to CWE-121 and say it allows arbitrary code execution in the mediaextractor process. CVSS 3.1 is 9.0 with network attack vector, no privileges, no user interaction, high complexity, and scope change.
Likely exposure
Exposure is limited to Samsung Mobile devices running Android O 8.1, P 9.x, Q 10.0, or R 11.0 before SMR May 2021 Release 1. Risk is highest where devices can receive or process untrusted media and are not centrally patched or retired.
Exploitation context
The provided bundle does not show CISA KEV listing or active exploitation evidence. The CVSS vector indicates remote reachability without privileges or user interaction, but high attack complexity. Treat as urgent for patch management, not as confirmed in-the-wild exploitation.
Researcher notes
The source bundle identifies the vulnerable parser function and library but does not provide deeper root-cause detail, proof-of-concept status, or model-specific patch matrices. Validation should focus on vendor patch level and presence of affected Android generations rather than speculative exploit testing.
Mitigation direction
- Install Samsung SMR May 2021 Release 1 or later where available.
- Retire or isolate affected Samsung devices that cannot receive the vendor fix.
- Restrict high-risk unmanaged devices from sensitive corporate resources.
- Monitor Samsung Mobile guidance for model-specific update availability.
Validation and detection
- Inventory Samsung devices by model, Android version, and security patch level.
- Confirm affected devices show May 2021 SMR Release 1 or later.
- Use MDM reporting to identify unpatched Android 8.1 through 11 Samsung devices.
- Document unsupported devices and enforce replacement or access restrictions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-121: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-25386 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H2.26Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9CriticalVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=5CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.