CVE-2016-20031
CVE-2016-20031 is a medium-severity vulnerability with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-798.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- CVSS v4: 6.8
- EPSS exploit prediction: 0% (5th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2016-10817
- Weakness: CWE-798
- Published:
- Last modified:
Description
ZKTeco ZKBioSecurity 3.0 contains a local authorization bypass vulnerability in visLogin.jsp that allows attackers to authenticate without valid credentials by spoofing localhost requests. Attackers can exploit the EnvironmentUtil.getClientIp() method which treats IPv6 loopback address 0:0:0:0:0:0:0:1 as 127.0.0.1 and authenticates using the IP as username with hardcoded password 123456 to access sensitive information and perform unauthorized actions.
Frequently asked questions
- What is CVE-2016-20031?
- ZKTeco ZKBioSecurity 3.0 contains a local authorization bypass vulnerability in visLogin.jsp that allows attackers to authenticate without valid credentials by spoofing localhost requests. Attackers can exploit the EnvironmentUtil.getClientIp() method which treats IPv6 loopback address 0:0:0:0:0:0:0:1 as 127.0.0.1 and authenticates using the IP as username with hardcoded password 123456 to access sensitive information and perform unauthorized actions.
- How severe is CVE-2016-20031?
- CVE-2016-20031 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2016-20031 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2016-20031?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2016-20031 have an EU (EUVD) identifier?
- Yes. CVE-2016-20031 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2016-10817.
- When was CVE-2016-20031 published?
- CVE-2016-20031 was published on 2026-03-16 and last updated on 2026-06-17.
References
- https://cxsecurity.com/issue/WLB-2016090003
- https://exchange.xforce.ibmcloud.com/vulnerabilities/116488
- https://packetstormsecurity.com/files/138571
- https://www.exploit-db.com/exploits/40327/
- https://www.vulncheck.com/advisories/zkteco-zkbiosecurity-local-authorization-bypass-via-vislogin-jsp
- https://www.zeroscience.mk/en/vulnerabilities/ZSL-2016-5367.php
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