CVE-2021-41551: Leostream Connection Broker 9.0.40.17 allows administrators to conduct directory traversal attacks by uploadin

Routine

MEDIUM 4.9DOWNGRADE

CVE-2021-41551 is a medium-severity flaw (CVSS 4.9) affecting connection broker. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Leostream Connection Broker 9.0.40.17 allows administrators to conduct directory traversal attacks by uploading z ZIP file that contains a symbolic link.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	4.9 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	1.3% (top 30%)
CISA exploited list	No
Weakness	CWE-59
Published	2022-01-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: leostream

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

Am I affected?

Timeline

2022-01-18 15:15 UTCPublished CVE record published
2026-06-17 04:08 UTCUpdated Record last modified

leostream connection broker DOWNGRADE

Affected: 9.0.40.17

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0.40.17

1. Check installed version

apt-cache policy connection-broker || rpm -q connection-broker || connection-broker --version

2. No fixed release: DOWNGRADE to a release before 9.0.40.17 (Debian / Ubuntu)

apt-cache madison connection-broker sudo apt install connection-broker=<VERSION_BEFORE_9.0.40.17> sudo apt-mark hold connection-broker

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

dnf --showduplicates list connection-broker sudo dnf downgrade connection-broker-<VERSION_BEFORE_9.0.40.17> sudo dnf versionlock add connection-broker

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-2021-41551?

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

Is CVE-2021-41551 being exploited?

CVE-2021-41551 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-2021-41551 affect?

CVE-2021-41551 affects connection broker. Severity is medium (CVSS 4.9). Leostream Connection Broker 9.0.40.17 allows administrators to conduct directory traversal attacks by uploading z ZIP file that contains a symbolic link.

How urgent is CVE-2021-41551?

Priority 35/100. No elevated risk signals yet.

Related CVEs

CVE-2021-41550 HIGH 7.2 DOWNGRADE Leostream Connection Broker 9.0.40.17 allows administrator to upload and execute Perl code.
CVE-2021-38157 MEDIUM 6.1 UPGRADE LeoStream Connection Broker 9.x before 9.0.34.3 allows Unauthenticated Reflected XSS via the /index.pl user pa

References

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