CyberSecBulletin
CVE-2025-47868NVD status: Analyzed

Apache NuttX RTOS: tools/bdf-converter.: Heap-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2025-47868 is a critical-severity heap-based buffer overflow vulnerability in Apache NuttX RTOS: tools/bdf-converter. from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 12.9.0 as the first without the flaw, so updating Apache NuttX RTOS: tools/bdf-converter. to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.8% chance of exploitation within 30 days, higher than 57% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Apache NuttX RTOS: tools/bdf-converter. to 12.9.0 or a later version.
  2. Update Nuttx to 12.9.0 or a later version.
  3. Read the advisory on lists.apache.org for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
ApacheApache NuttX RTOS: tools/bdf-converter.6.9 up to, but not including, 12.9.012.9.0
ApacheNuttx6.9 up to, but not including, 12.9.012.9.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

Out-of-bounds Write resulting in possible Heap-based Buffer Overflow vulnerability was discovered in tools/bdf-converter font conversion utility that is part of Apache NuttX RTOS repository. This standalone program is optional and neither part of NuttX RTOS nor Applications runtime, but active bdf-converter users may be affected when this tool is exposed to external provided user data data (i.e. publicly available automation). This issue affects Apache NuttX: from 6.9 before 12.9.0. Users are recommended to upgrade to version 12.9.0, which fixes the issue.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Heap-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the heap.

How developers prevent this class of flaw

  • Pre-design: Use a language or compiler that performs automatic bounds checking.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Heap-based Buffer Overflow vulnerabilities (CWE-122)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Recent Heap-based Buffer Overflow vulnerabilities

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