Security readout for executives and security teams
Plain-English summary
This issue can permanently disable certain Ledger hardware wallet devices during the MCU firmware update process. The business impact is device availability: affected custody or signing workflows could lose a device, but the provided sources indicate physical access is required and do not show active exploitation.
Executive priority
Handle as a moderate operational resilience issue. Prioritize teams using Ledger devices for custody, treasury, or signing workflows, especially where device loss would interrupt business operations. The urgency is lower than remotely exploitable flaws because the source bundle indicates physical access is required.
Technical view
CVE-2025-15645 is a CWE-1284 validation flaw in MCU firmware flashing for Ledger Nano X, Flex, and Stax. Missing validation of the reset_handler parameter can put the device into an unrecoverable boot fault. CVSS 4.0 is 5.1, with high availability impact and no stated confidentiality or integrity impact.
Likely exposure
Exposure is most relevant to organizations or users operating Ledger Nano X, Flex, or Stax devices. The source bundle indicates physical attack vector and does not identify remote network exposure. Version data in the supplied affected list is limited and should be confirmed against Ledger guidance.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle. No cited source in the bundle states active exploitation. The documented precondition is physical access or control over the firmware flashing process, with low attack complexity once that condition exists.
Researcher notes
The record attributes the issue to missing reset_handler validation during MCU flashing. Avoid assuming broader device compromise: supplied scoring shows availability impact only. The affected-version metadata appears sparse, so product/version confirmation should rely on Ledger’s bulletin rather than extrapolation.
Mitigation direction
- Review Ledger Security Bulletin 021 for official remediation and affected-version guidance.
- Use only trusted Ledger firmware update tooling and verified update sources.
- Restrict physical access to hardware wallets and update workstations.
- Quarantine devices that fail after firmware update and follow Ledger support guidance.
Validation and detection
- Inventory Ledger Nano X, Flex, and Stax devices in use.
- Confirm firmware and MCU update status against Ledger Security Bulletin 021.
- Review custody procedures for who can initiate firmware updates.
- Check incident logs for failed or abnormal Ledger firmware update attempts.
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-1284: 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 lookupCVE-2025-15645 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.1 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
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.
SSVC decision data
CVSS vector scores
2 official scoresWe 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:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H0.93.6VulnCheckVulnerability scoring details
Base CVSS 4.0 score
5.1MediumVector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
4.6MediumVector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Ledger Security Bulletin 021CVE reference, VulnCheck · vendor-advisory
- https://www.vulncheck.com/advisories/ledger-nano-x-flex-stax-mcu-firmware-update-denial-of-serviceCVE reference, VulnCheck · third-party-advisory
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.
Improper Validation of Specified Quantity in Input
Improper Validation of Specified Quantity in Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.