Cyber Resilience

CVE-2023-38406

Critical

Published: 06 November 2023

Published
06 November 2023
Modified
04 November 2025
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0011 28.2th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-38406 is a critical-severity Improper Handling of Exceptional Conditions (CWE-755) vulnerability in Frrouting Frrouting. Its CVSS base score is 9.8 (Critical).

Operationally, ranked at the 28.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

bgpd/bgp_flowspec.c in FRRouting (FRR) before 8.4.3 mishandles an nlri length of zero, aka a "flowspec overflow."

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

frrouting
frrouting
≤ 8.4.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-755

Provides defined handling (alert and additional actions) for the exceptional condition of audit logging failure.

addresses: CWE-755

Supplies a concrete handling action (safe mode) for exceptional conditions, mitigating risks from improper or absent handling that could allow continued attacks.

addresses: CWE-755

By preparing users for contingency scenarios, the control promotes proper handling of exceptional conditions instead of default or unsafe behaviors.

addresses: CWE-755

An updated contingency plan defines current actions for exceptional conditions, reducing the window for attackers to exploit improper handling leading to system failure.

addresses: CWE-755

Procedures ensure proper handling of exceptional conditions to support effective incident response.

addresses: CWE-755

Incident response testing confirms proper handling of exceptional conditions to limit exploit impact.

addresses: CWE-755

Gives users guidance on incident handling, reducing improper handling of exceptional conditions that could stem from exploited weaknesses.

addresses: CWE-755

Enforces structured response to exceptional conditions so the system cannot remain in an unsafe state.

References