Denial of service caused by a bug in the JSON parser

published 2023-07-13 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-33020

cvss: 4.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits: 0; none known

Specially crafted string can cause a buffer overrun in the JSON parser library leading to a crash of the Zabbix Server or a Zabbix Proxy.

Patch / fix

distros 1

zabbix Debian 14, Debian 13 1:6.0.23+dfsg-1

debian advisories DEBIAN-CVE-2023-29451

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-10-22)

Exploit prediction

0.78% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Zabbix Zabbix

Classification

Weakness

CWE-20 Improper Input Validation
CWE-787 Out-of-bounds Write

References

support.zabbix.com /browse/ZBX-22587
vendor-advisory
lists.debian.org /debian-lts-announce/2023/08/msg00027.html

Sources

CVE List CVE-2023-29451
NVD CVE-2023-29451

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.

Summary