No exploitation reportedFix available

CVE-2020-29299

Q: Is CVE-2020-29299 actively exploited?

Active exploitation of CVE-2020-29299 has not been confirmed. Its EPSS score was 2.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-29299?

CVE-2020-29299 has a CVSS v3 base score of 7.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2020-12-27
Fixed in1.33
WeaknessCWE-77

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Certain Zyxel products allow command injection by an admin via an input string to chg_exp_pwd during a password-change action. This affects VPN On-premise before ZLD V4.39 week38, VPN Orchestrator before SD-OS V10.03 week32, USG before ZLD V4.39 week38, USG FLEX before ZLD V4.55 week38, ATP before ZLD V4.55 week38, and NSG before 1.33 patch 4.

Timeline

dates in UTC

2020-12-2706:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-29299?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-29299?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Zyxel nsg firmwareversion to verify

Branch	Affected	Fixed in	Source
1.33	< 1.33	1.33	NVD
1.33	= 1.33	no fix published	NVD

Zyxel zldversion to verify

Branch	Affected	Fixed in	Source
4.55	< 4.55	4.55	NVD
4.39	< 4.39	4.39	NVD

Zyxel usg flex firmwareversion to verify

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Zyxel nsg firmware to 1.33

Advisories and patches

www.zyxel.comVendor Advisory
www.zyxel.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.2read 2026-10-23
NVDCVSS 2.09read 2026-10-23
NVDweakness (CWE)CWE-77read 2026-10-23
FIRST EPSSEPSS score2.4 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Published: 2020-12-27
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-29299?

Is CVE-2020-29299 actively exploited?

Active exploitation of CVE-2020-29299 has not been confirmed. Its EPSS score was 2.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-29299?

CVE-2020-29299 has a CVSS v3 base score of 7.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

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