CVE-2021-35030
A vulnerability was found in the CGI program in Zyxel GS1900-8 firmware version V2.60, that did...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2021-35030- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-21677
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.
- Record
EUVD-2021-21677- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-g78g-pgq7-f6cr No score
A vulnerability was found in the CGI program in Zyxel GS1900-8 firmware version V2.60, that did...
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.
- Record
GHSA-g78g-pgq7-f6cr- Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-35030- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 2.3 Low
AV:A/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
- zyxel gs1900-8 firmware
- zyxel gs1900-10hp firmware
- zyxel gs1900-16 firmware
- zyxel gs1900-24 firmware
- zyxel gs1900-24e firmware
- zyxel gs1900-24ep firmware
- zyxel gs1900-24hp firmware
- zyxel gs1900-24hpv2 firmware
- zyxel gs1900-48 firmware
- zyxel gs1900-48hp firmware
- zyxel gs1900-48hpv2 firmware
- zyxel gs1900-8hp firmware
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-35030 is a low vulnerability (CVSS 3.5) in Zyxel Gs1900-8 Firmware, published July 26, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.27%, the 19th percentile. No source names a fixed version.