PatchTheCVECVE-2016-5673: UltraVNC Repeater before 1300 does not restrict destination IP addresses or TCP ports, which allows remote att
CVE-2016-5673 is a high-severity flaw (CVSS 7.5) affecting repeater. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
UltraVNC Repeater before 1300 does not restrict destination IP addresses or TCP ports, which allows remote attackers to obtain open-proxy functionality by using a :: substring in between the IP address and port number.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.9% (top 21%) |
| CISA exploited list | No |
| Weakness | CWE-284 |
| Published | 2016-08-25 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2016-5673?
repeater: upgrade to newer than 1201. Exact commands for each OS are on this page.
Is CVE-2016-5673 being exploited?
CVE-2016-5673 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2016-5673 affect?
CVE-2016-5673 affects repeater. Severity is high (CVSS 7.5). UltraVNC Repeater before 1300 does not restrict destination IP addresses or TCP ports, which allows remote attackers to obtain open-proxy functionality by using a :: substring in between the IP address and port number.
How urgent is CVE-2016-5673?
Priority 51/100. High severity; Remotely exploitable, no login, no user action