CVE-2020-13364
A backdoor in certain Zyxel products allows remote TELNET access via a CGI script.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.15% probability · 65th percentile
- CISA KEV
- Not listed
- Affected
- zyxel/nas326 firmware · zyxel/nas520 firmware · zyxel/nas540 firmware · zyxel/nas542 firmware
- Source
- cve@mitre.org
References
- https://www.zyxel.com/support/Zyxel-security-advisory-for-NAS-remote-access-vulnerability.shtmlVendor Advisory
- https://www.zyxel.com/us/en/support/security_advisories.shtmlVendor Advisory
- https://www.zyxel.com/support/Zyxel-security-advisory-for-NAS-remote-access-vulnerability.shtmlVendor Advisory
- https://www.zyxel.com/us/en/support/security_advisories.shtmlVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.