Security readout for executives and security teams
Plain-English summary
A malicious USB device connected during startup can trigger a memory-writing error in GRUB2. A successful attack could crash the bootloader, preventing normal startup, and may corrupt data. Exploitation requires physical access and is described as complex, limiting broad attack likelihood.
Executive priority
Treat this as a targeted physical-access resilience issue, not an internet-scale emergency. Prioritize systems in public, shared, remote, or weakly controlled locations. For well-controlled data centers, handle through normal patch governance while maintaining strict console and USB access controls.
Technical view
GRUB2 mishandles string conversion while processing USB device information with inconsistent length values, causing an out-of-bounds write classified as CWE-131. The CVSS 3.1 score is 4.8, reflecting physical access, high complexity, high availability impact, and possible low integrity impact.
Likely exposure
The bundle identifies GRUB2 packages in Red Hat Enterprise Linux 7 through 10 and Red Hat OpenShift Container Platform 4 as affected. Systems where untrusted people can attach USB devices during boot or reboot have the clearest exposure. Exact affected and fixed package versions are not provided.
Exploitation context
The attacker must locally connect a specially configured USB device during the boot sequence. No privileges or user interaction are required, but physical access and high attack complexity reduce practical reach. The CVE is not listed as known exploited, and the supplied sources provide no evidence of active exploitation.
Researcher notes
The supplied evidence supports an out-of-bounds write and likely denial of service, with possible data corruption. It does not establish code execution, reliable exploitation, public exploit availability, or active attacks. Fixed versions and vendor-specific remediation details are absent, so package-level conclusions require current Red Hat guidance.
Mitigation direction
- Check Red Hat guidance for corrected GRUB2 or platform packages and apply supported updates when available.
- Restrict physical access to systems, consoles, and exposed USB ports.
- Prevent unauthorized USB devices from remaining connected during startup or maintenance reboots.
- Prioritize externally accessible, shared-site, kiosk, edge, and unattended systems for review.
Validation and detection
- Inventory RHEL 7 through 10 and OpenShift 4 systems using the affected GRUB2 packages.
- Compare installed bootloader and platform package versions with current Red Hat guidance.
- Identify systems where untrusted users can access USB ports during boot or reboot.
- Confirm relevant updates are deployed after Red Hat publishes fixed package information.
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-131: 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 lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-61661 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
- 4.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/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.
SSVC decision data
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:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H0.54.2redhatVulnerability scoring details
Base CVSS 3.1 score
4.8MediumVector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:L/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.
- Source timelineredhat
Reported to Red Hat.
- Source timelineredhat
Made public.
- 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
- https://access.redhat.com/security/cve/CVE-2025-61661CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2413827CVE reference, redhat · issue-tracking, x_refsource_REDHAT
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.
Incorrect Calculation of Buffer Size
Incorrect Calculation of Buffer Size represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.