Skip to content
Fencer Vulns
critical 9.8

CVE-2023-38406 json

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

published 2023-11-06 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-42223

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

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

Patch / fix

  • frrouting frrouting 8.4.3
  • frr Debian 12 8.4.4-1.1~deb12u1
  • frr Debian 14, Debian 13 8.4.4-1

debian advisories DEBIAN-CVE-2023-38406

  • frr Ubuntu 22.04 LTS 8.1-1ubuntu1.8
  • frr Ubuntu Pro 20.04 LTS 7.2.1-1ubuntu0.2+esm2

ubuntu advisories UBUNTU-CVE-2023-38406

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • frr RHEL 9 8.3.1-11.el9_3.2
  • frr-selinux RHEL 9 8.3.1-11.el9_3.2
  • frr RHEL 8 7.5.1-13.el8_9.3
  • frr-selinux RHEL 8 7.5.1-13.el8_9.3
  • frr RHEL 9.0 EUS 8.0-5.el9_0.3
  • frr RHEL 8.6 EUS 7.5-11.el8_6.7
  • frr RHEL 9.2 EUS 8.3.1-5.el9_2.4
  • frr-selinux RHEL 9.2 EUS 8.3.1-5.el9_2.4

red hat advisories RHSA-2024:1152RHSA-2024:1113RHSA-2024:1093RHSA-2024:0574RHSA-2024:0477RHSA-2024:0130

  • frr SLE Module for Server Applications 15 SP6, SLE Module for Server Applications 15 SP5, openSUSE Leap 15.6 +1 more 8.5.6-150500.4.30.1
  • frr SLES for SAP 15 SP4, SLES for SAP 15 SP3, SLES 15 SP4-LTSS +7 more 7.4-150300.4.26.1
  • frr SLE Module for Server Applications 15 SP5, openSUSE Leap 15.5 8.4-150500.4.15.1

suse advisories SUSE-SU-2024:4090-1SUSE-SU-2024:2245-1SUSE-SU-2023:4663-1

  • frr openSUSE Tumbleweed 8.4-8.1

opensuse advisories openSUSE-SU-2024:13487-1

  • frr AlmaLinux 9 8.3.1-11.el9_3.2.alma.1
  • frr-selinux AlmaLinux 9 8.3.1-11.el9_3.2.alma.1
  • frr AlmaLinux 8 7.5.1-13.el8_9.3.alma.1
  • frr-selinux AlmaLinux 8 7.5.1-13.el8_9.3.alma.1

almalinux advisories ALSA-2024:0477ALSA-2024:0130

  • frr Rocky Linux 8 7.5.1-13.el8_9.3

rocky linux advisories RLSA-2024:0130

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-38406 updated cvss 7.5

ffr: Flowspec overflow in bgpd/bgp_flowspec.c

  • Red Hat Enterprise Linux AppStream (v. 8) frr 7.5.1-13.el8_9.3, frr-selinux 7.5.1-13.el8_9.3
    fixed: vendor fix RHSA-2024:0130
  • Red Hat Enterprise Linux AppStream (v. 9) frr 8.3.1-11.el9_3.2, frr-selinux 8.3.1-11.el9_3.2
    fixed: vendor fix RHSA-2024:0477
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) frr 7.5-11.el8_6.7
    fixed: vendor fix RHSA-2024:1113
  • Red Hat Enterprise Linux AppStream EUS (v.8.8) frr 7.5.1-7.el8_8.5, frr-selinux 7.5.1-7.el8_8.5
    fixed: vendor fix RHSA-2024:0574
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) frr 8.0-5.el9_0.3
    fixed: vendor fix RHSA-2024:1152
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) frr 8.3.1-5.el9_2.4, frr-selinux 8.3.1-5.el9_2.4
    fixed: vendor fix RHSA-2024:1093

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

1.13% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

Weakness
  • CWE-755 Improper Handling of Exceptional Conditions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.