SKYSEA Client View Improper Authentication
CVE-2016-7836 is a critical-severity improper authentication vulnerability in SKYSEA Client View from Sky, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SKYSEA Client View versions: Ver.11.221.03 and earlier. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on October 14, 2025, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of SKYSEA Client View you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Read the advisory on skyseaclientview.net for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Sky | SKYSEA Client View | Ver.11.221.03 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 10.0 | High | NVD |
Official description
SKYSEA Client View Ver.11.221.03 and earlier allows remote code execution via a flaw in processing authentication on the TCP connection with the management console program.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- securityfocus.com/bid/95062Third Party Advisory, VDB Entry
- jvn.jp/en/jp/JVN84995847/index.htmlThird Party Advisory, VDB Entry
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-7836US Government Resource
Technical write-ups (may include proof of concept)
- skygroup.jp/security-info/170308.htmlExploit, Technical Description, Third Party Advisory
Other vulnerabilities in SKYSEA Client View
- 8.5 High severity
- 8.5 High severity
- 8.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
Juniper ScreenOS Improper Authentication Exploited
- 9.8 Critical severity
Adobe ColdFusion Authentication Bypass Exploited
Spotted an error? Tell us.