CVE-2025-0890: zyxel sbg3300-n000_firmware Improper Authentication
Vulnerability summary
CVE-2025-0890 is a critical (CVSS 9.8) Improper Authentication vulnerability in zyxel sbg3300-n000_firmware. EPSS estimates a 13.65% chance of exploitation in the next 30 days, higher than 96.4% of scored vulnerabilities.
Timeline
- 04-02-2025PublishedVulnerability first disclosed.
- 12-02-2025Last modifiedVulnerability information updated.
Description
**UNSUPPORTED WHEN ASSIGNED** Insecure default credentials for the Telnet function in the legacy DSL CPE Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an attacker to log in to the management interface if the administrators have the option to change the default credentials but fail to do so.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
13.65%
Chance of exploitation in the next 30 days
Percentile
96%
Versus all other CVEs
30-day change
+0.11 pp
From 13.54% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- CWE-522Insufficiently Protected CredentialsThe product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.
Affected systems
1 vendor · 15 products
References
1 links- www.zyxel.com/global/…Vendor Advisory