CVE-2016-5791: An Improper Authentication issue was discovered in JanTek JTC-200, all versions

This week

CRITICAL 9.8REMOTEMITIGATE

CVE-2016-5791 is a critical-severity flaw (CVSS 9.8) affecting jtc-200 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An Improper Authentication issue was discovered in JanTek JTC-200, all versions. The improper authentication could provide an undocumented BusyBox Linux shell accessible over the TELNET service without any authentication.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-287
Published	2017-10-13
Last modified	2026-06-17

Publisher (CNA): ICS-CERT · Vendor: jantek

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-10-13 03:29 UTCPublished CVE record published
2026-06-17 00:50 UTCUpdated Record last modified

jantek jtc-200 firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
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-2016-5791?

jtc-200 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-5791 being exploited?

CVE-2016-5791 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-2016-5791 affect?

CVE-2016-5791 affects jtc-200 firmware. Severity is critical (CVSS 9.8). An Improper Authentication issue was discovered in JanTek JTC-200, all versions. The improper authentication could provide an undocumented BusyBox Linux shell accessible over the TELNET service without any authentication.

How urgent is CVE-2016-5791?

Priority 60/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2016-5789 HIGH 8.0 MITIGATE A Cross-site Request Forgery issue was discovered in JanTek JTC-200, all versions

References

← Back to latest CVEs