Security readout for executives and security teams
Plain-English summary
CVE-2023-21420 affects Samsung Mobile Devices running Android 10 or 11 with Teegris before Samsung’s January 2023 SMR Release 1. A local, low-privileged attacker could trigger arbitrary code execution. The business concern is compromised device integrity and availability on older, unpatched Samsung fleets.
Executive priority
Treat as high priority for any managed Samsung Android 10 or 11 fleet because successful exploitation could allow code execution and serious integrity or availability impact. Urgency is lower where devices are already patched beyond January 2023.
Technical view
The issue is a CWE-134 externally controlled format string vulnerability in STST TA. The CVSS 3.1 score is 7.3 with local access, low attack complexity, low privileges, no user interaction, and high integrity and availability impact. The source bundle identifies remediation by the SMR Jan-2023 Release 1 boundary.
Likely exposure
Exposure is limited to Samsung Mobile Devices on Android Q(10) or R(11) with Teegris that have not received SMR Jan-2023 Release 1 or later. The provided sources do not list specific models or regions.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle, and no cited source states active exploitation. Attack prerequisites are local access and low privileges, with no user interaction required according to the CVSS vector.
Researcher notes
Evidence is concise: CVE metadata and Samsung’s January 2023 advisory identify the vulnerability class, affected platform boundary, and code execution impact. The bundle does not provide exploit details, model granularity, active exploitation evidence, or compensating controls beyond updating through Samsung guidance.
Mitigation direction
- Apply Samsung SMR Jan-2023 Release 1 or later to affected devices.
- Prioritize managed Android 10 and 11 Samsung devices with Teegris.
- Check Samsung’s advisory for device-specific update availability.
- Replace or isolate devices that cannot receive the required security update.
Validation and detection
- Inventory Samsung devices by Android version, model, and security patch level.
- Confirm whether devices use Teegris where this data is available.
- Verify security patch status against SMR Jan-2023 Release 1 or later.
- Review MDM compliance reports for outdated Samsung Android 10 or 11 devices.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-134: 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-2023-21420 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/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:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H1.85.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://security.samsungmobile.com/securityUpdate.smsb?year=2023&month=01CVE reference
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.
Use of Externally-Controlled Format String
Use of Externally-Controlled Format String represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.