Cyber Resilience

CVE-2021-35030

Low

Published: 26 July 2021

Published
26 July 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 3.5 CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L
EPSS Score 0.0011 29.9th percentile
Risk Priority 7 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-35030 is a low-severity Cross-site Scripting (CWE-79) vulnerability in Zyxel Gs1900-8 Firmware. Its CVSS base score is 3.5 (Low).

Operationally, ranked at the 29.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A vulnerability was found in the CGI program in Zyxel GS1900-8 firmware version V2.60, that did not properly sterilize packet contents and could allow an authenticated, local user to perform a cross-site scripting (XSS) attack via a crafted LLDP packet.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

zyxel
gs1900-8 firmware
≤ 2.70
zyxel
gs1900-8hp firmware
≤ 2.70
zyxel
gs1900-10hp firmware
≤ 2.70
zyxel
gs1900-16 firmware
≤ 2.70
zyxel
gs1900-24e firmware
≤ 2.70
zyxel
gs1900-24ep firmware
≤ 2.70
zyxel
gs1900-24 firmware
≤ 2.70
zyxel
gs1900-24hp firmware
≤ 2.70
zyxel
gs1900-24hpv2 firmware
≤ 2.70
zyxel
gs1900-48 firmware
≤ 2.70
+2 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References