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Fencer Vulns
high 7.5

CVE-2021-43612 json

In lldpd before 1.0.13, when decoding SONMP packets in the sonmp_decode function, it's possible to trigger an out-of-bounds heap read via s…

published 2023-04-15 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-30526

cvss
7.5
version 3.1, CNA
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

In lldpd before 1.0.13, when decoding SONMP packets in the sonmp_decode function, it's possible to trigger an out-of-bounds heap read via short SONMP packets.

Patch / fix

  • lldpd_project lldpd 1.0.13
  • lldpd Debian 14, Debian 13, Debian 12 1.0.13-1

debian advisories DEBIAN-CVE-2021-43612

  • lldpd RHEL 9 1.0.18-4.el9

red hat advisories RHSA-2024:9158

  • lldpd openSUSE Tumbleweed 1.0.13-1.1

opensuse advisories openSUSE-SU-2024:11635-1

  • lldpd AlmaLinux 9 1.0.18-4.el9

almalinux advisories ALSA-2024:9158

  • lldpd Rocky Linux 9 1.0.18-4.el9

rocky linux advisories RLSA-2024:9158

  • lldpd Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 1.0.13-r0

alpine advisories ALPINE-CVE-2021-43612

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2021-43612 updated cvss 7.3

lldpd: out-of-bounds read when decoding SONMP packets

  • Red Hat Enterprise Linux 8 lldpd
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 9) lldpd 1.0.18-4.el9
    fixed: vendor fix RHSA-2024:9158

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
yes
Technical impact
partial
Assessed
21 mo ago

Exploit prediction

1.14% 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
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness

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.