CVE-2021-36717: Synerion TimeNet version 9.21 contains a directory traversal vulnerability where, on the "Name" parameter, the

Routine

MEDIUM 5.4DOWNGRADE

CVE-2021-36717 is a medium-severity flaw (CVSS 5.4) affecting timenet. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Synerion TimeNet version 9.21 contains a directory traversal vulnerability where, on the "Name" parameter, the attacker can return to the root directory and open the host file. This might give the attacker the ability to view restricted files, which could provide the attacker with more information required to further compromise the system.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-22
Published	2021-09-07
Last modified	2026-06-17

Publisher (CNA): Israel National Cyber Directorate · Vendor: synerion

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

Am I affected?

Timeline

2021-09-07 12:15 UTCPublished CVE record published
2026-06-17 03:59 UTCUpdated Record last modified

synerion timenet DOWNGRADE

Affected: 9.21

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.21

1. Check installed version

apt-cache policy timenet || rpm -q timenet || timenet --version

2. No fixed release: DOWNGRADE to a release before 9.21 (Debian / Ubuntu)

apt-cache madison timenet sudo apt install timenet=<VERSION_BEFORE_9.21> sudo apt-mark hold timenet

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list timenet sudo dnf downgrade timenet-<VERSION_BEFORE_9.21> sudo dnf versionlock add timenet

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2021-36717?

timenet: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-36717 being exploited?

CVE-2021-36717 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-2021-36717 affect?

CVE-2021-36717 affects timenet. Severity is medium (CVSS 5.4). Synerion TimeNet version 9.21 contains a directory traversal vulnerability where, on the "Name" parameter, the attacker can return to the root directory and open the host file. This might give the attacker the ability to view restricted fil

How urgent is CVE-2021-36717?

Priority 34/100. No elevated risk signals yet.

References

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