CVE-2021-3297

On Zyxel NBG2105 V1.00(AAGU.2)C0 devices, setting the login cookie to 1 provides administrator access.

CVSS v3 7.8 HIGH
CVSS v2.0 7.2 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

7.2^/10

CVSS v2.0 : HIGH

Vector : AV:L/AC:L/Au:N/C:C/I:C/A:C

Exploitability : 3.9 / Impact : 10.0

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

References

Link	Resource
https://codeberg.org/nieldk/vulnerabilities/src/branch/main/zyxel%20nbg2105/Admin%20bypass
https://github.com/nieldk/vulnerabilities/blob/main/zyxel%20nbg2105/Admin%20bypass	Exploit Third Party Advisory
https://www.zyxel.com/support/SupportLandingSR.shtml?c=gb&l=en&kbid=M-01490&md=NBG2105	Product Vendor Advisory
https://www.zyxel.com/us/en/support/security_advisories.shtml	Vendor Advisory
https://github.com/nieldk/vulnerabilities/blob/main/zyxel%20nbg2105/Admin%20bypass	Exploit Third Party Advisory
https://www.zyxel.com/support/SupportLandingSR.shtml?c=gb&l=en&kbid=M-01490&md=NBG2105	Product Vendor Advisory
https://www.zyxel.com/us/en/support/security_advisories.shtml	Vendor Advisory

Configurations

Configuration 1 (hide)

AND

cpe:2.3:o:zyxel:nbg2105_firmware:v1.00\(aagu.2\)c0:*:*:*:*:*:*:*

cpe:2.3:h:zyxel:nbg2105:-:*:*:*:*:*:*:*

History

25 Nov 2025, 18:15

Type	Values Removed	Values Added
References		() https://codeberg.org/nieldk/vulnerabilities/src/branch/main/zyxel%20nbg2105/Admin%20bypass -

Information

Published : 2021-01-26 18:16

Updated : 2025-11-25 18:15

NVD link : CVE-2021-3297

Mitre link : CVE-2021-3297

CVE.ORG link : CVE-2021-3297

JSON object : View

Products Affected

zyxel

nbg2105
nbg2105_firmware

CWE

CWE-287

Improper Authentication

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