9

CVE-2020-13364: zyxel nas326_firmware

CVSS: 9.0v2.0HighModified
Published 06-08-2020Last modified 04-08-2024

Vulnerability summary

CVE-2020-13364 is a high (CVSS 9.0) vulnerability in zyxel nas326_firmware. EPSS estimates a 1.15% chance of exploitation in the next 30 days, higher than 66.4% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.0/10
010
High · v2.0 (NVD)
EPSS score
1.15%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 06-08-2020
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

A backdoor in certain Zyxel products allows remote TELNET access via a CGI script. This affects NAS520 V5.21(AASZ.4)C0, V5.21(AASZ.0)C0, V5.11(AASZ.3)C0, and V5.11(AASZ.0)C0; NAS542 V5.11(ABAG.0)C0, V5.20(ABAG.1)C0, and V5.21(ABAG.3)C0; NSA325 v2_V4.81(AALS.0)C0 and V4.81(AAAJ.1)C0; NSA310 4.22(AFK.0)C0 and 4.22(AFK.1)C0; NAS326 V5.21(AAZF.8)C0, V5.11(AAZF.4)C0, V5.11(AAZF.2)C0, and V5.11(AAZF.3)C0; NSA310S V4.75(AALH.2)C0; NSA320S V4.75(AANV.2)C0 and V4.75(AANV.1)C0; NSA221 V4.41(AFM.1)C0; and NAS540 V5.21(AATB.5)C0 and V5.21(AATB.3)C0.

CVSS metrics

4 scores · 2 sources · 3 versions

EPSS trend

Probability

1.15%

Chance of exploitation in the next 30 days

Percentile

66%

Versus all other CVEs

30-day change

0.00 pp

From 1.15% on 20-09-2026

20-09-202620-10-2026
EPSS score
1.15%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Zyxel4 products

1 vendor · 4 products

References

2 links