Certain Zyxel products have a locally accessible binary that allows a non-root user to generate a password for an undocumented user account that can be used for a TELNET session as root. 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.
AI analysis not yet available
Plain-English explanation, risk summary, and remediation steps will appear here once AI analysis is complete.
No Fix Known
No patch has been released yet. Apply workarounds or mitigations where available.
| Vendor | Product | Versions | Fixed In |
|---|---|---|---|
| zyxel | nas326_firmware | v5.21\(aazf.9\)c0 | - |
| zyxel | nas520_firmware | v5.21\(aasz.5\)c0 |
Published
CVE disclosed publicly
Last Modified
Most recent update
Indexed to CVEInsight
Added to this platform
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4
Affected Products
4
References
zyxel / nas326_firmware
| - |
| zyxel | nas540_firmware | v5.21\(aatb.6\)c0 | - |
| zyxel | nas542_firmware | v5.21\(abag.6\)c0 | - |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability
Impact