Auth bypass in Zyxel Nbg2105
CVE-2021-3297
On Zyxel NBG2105 V1.00(AAGU.2)C0 devices, setting the login cookie to 1 provides administrator access.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.205 (97.4th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.205 · newest: 0.205 · change: 0.000
Affected products
- Zyxel Nbg2105
- Zyxel Nbg2105 Firmware — versions v1.00(aagu.2)c0, v1.00\(aagu.2\)c0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.zyxel.com/us/en/support/security_advisories.shtml (Vendor Advisory)
- www.zyxel.com/support/SupportLandingSR.shtml (Product, Vendor Advisory)
- github.com/nieldk/vulnerabilities/blob/main/zyxel nbg2105/Admin bypass (Exploit, Third Party Advisory)
- codeberg.org/nieldk/vulnerabilities/src/branch/main/zyxel nbg2105/Admin bypass
Frequently asked questions
- What is CVE-2021-3297?
- CVE-2021-3297 is a high-severity vulnerability in Zyxel Nbg2105, classified under Improper Authentication. CVSS score: 7.8/10. Published 2021-01-26.
- How severe is CVE-2021-3297?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2021-3297 known to be exploited?
- 21 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.