Quantum Secular Labs / Blog / Advisories
CVE-2016-20030: ZKTeco ZKBioSecurity: Authentication bypass
CVE-2016-20030 is rated critical with a CVSS v3.1 base score of 9.8. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.
Vulnerability description
ZKTeco ZKBioSecurity 3.0 contains a user enumeration vulnerability that allows unauthenticated attackers to discover valid usernames by submitting partial characters via the username parameter. Attackers can send requests to the authLoginAction!login.do script with varying username inputs to enumerate valid user accounts based on application responses.
Severity breakdown
CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
- Attack complexity: Low. No special conditions; the attack can be repeated reliably.
- Privileges required: None. No account or prior access is needed.
- User interaction: None. No action from any user is needed.
- Scope: Unchanged. Impact stays within the vulnerable component.
- Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
- Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
- Availability impact: High. Total loss of availability; the component can be shut down.
Underlying weakness
CWE-551: Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
If a web server does not fully parse requested URLs before it examines them for authorization, it may be possible for an attacker to bypass authorization protection.