fprime vulnerability

F´ (F Prime) is a framework that enables development and deployment of spaceflight and other embedded software applications. Prior to 4.3.0, Svc::FileDownlink SendPartial range validation is vulnerable because unchecked startOffset plus length arithmetic bypasses the range check and stores a wrapped m_endOffset that is inconsistent with m_byteOffset. When an existing source file is larger than a valid startOffset and a SendPartial command supplies a length whose U32 sum with that offset wraps below the file size, under standard F Prime assertion handling, the first data-packet transition reaches FW_ASSERT and aborts or resets the process, causing denial of service. This issue is fixed in version 4.3.0.

Published 14 Oct 2026Updated 20 Oct 20266 sources
CVSS 6.5

What happened

F´ (F Prime) is a framework that enables development and deployment of spaceflight and other embedded software applications. Prior to 4.3.0, Svc::FileDownlink SendPartial range validation is vulnerable because unchecked startOffset plus length arithmetic bypasses the range check and stores a wrapped m_endOffset that is inconsistent with m_byteOffset. When an existing source file is larger than a valid startOffset and a SendPartial command supplies a length whose U32 sum with that offset wraps below the file size, under standard F Prime assertion handling, the first data-packet transition reaches FW_ASSERT and aborts or resets the process, causing denial of service. This issue is fixed in version 4.3.0.

Affected versions

fprime: < 4.3.0 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.