Security readout for executives and security teams
Plain-English summary
CVE-2019-16256, known as Simjacker, affects some Samsung devices using UICCs that include the S@T Browser. A remote attacker could use specially formed SIM Toolkit SMS instructions to obtain sensitive mobile information such as location and IMEI, or trigger certain commands.
Executive priority
Treat this as urgent for organizations with managed Samsung mobile fleets or sensitive mobile users. The key business risk is covert mobile surveillance or command execution through carrier/SIM infrastructure, with exposure details requiring carrier confirmation.
Technical view
The issue is in the SIMalliance Toolbox Browser on the UICC, reachable through SIM Toolkit instructions delivered by SMS. The CVE records network attack, low complexity, no privileges, and no user interaction, with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely in mobile fleets with affected Samsung devices or carrier-issued UICCs containing S@T Browser. The provided sources do not enumerate exact Samsung models, UICC vendors, carrier profiles, or firmware versions.
Exploitation context
CISA KEV lists CVE-2019-16256 as known exploited. The CVE and AdaptiveMobile reference describe remote SMS-based abuse for surveillance-related outcomes, including location and IMEI retrieval. No source bundle evidence provides safe patch status or full affected inventory.
Researcher notes
The source bundle supports critical severity and KEV exploitation, but lacks model-level affected data and authoritative patch details. Validation should focus on UICC/SIM profile presence, carrier-side controls, and vendor guidance rather than exploit reproduction.
Mitigation direction
- Ask mobile operators whether deployed UICCs include S@T Browser and whether filtering is enabled.
- Review Samsung, carrier, and SIM vendor advisories for replacement, OTA SIM updates, or network controls.
- Prioritize high-risk mobile users handling sensitive operations, executive travel, or regulated data.
- Avoid inventing device exclusions; base remediation scope on carrier and vendor confirmation.
Validation and detection
- Inventory Samsung devices and associated carrier UICCs across managed mobile fleets.
- Confirm with carriers whether S@T Browser is present or disabled on issued SIM profiles.
- Review mobile security telemetry for suspicious SIM Toolkit or unusual silent SMS activity, if available.
- Check CISA KEV tracking and vendor guidance for required remediation timelines.
Public sources used
Michael Williams reviewed this cited source version on .
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CVE-2019-16256 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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.
CISA KEV status
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.adaptivemobile.com/blog/simjacker-next-generation-spying-over-mobileCVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-16256CVE reference · government-resource
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.