CVE-2021-45035: Velneo vClient on its 28.1.3 version, does not correctly check the certificate of authenticity by default

Routine

MEDIUM 6.3DOWNGRADE

CVE-2021-45035 is a medium-severity flaw (CVSS 6.3) affecting vclient. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Velneo vClient on its 28.1.3 version, does not correctly check the certificate of authenticity by default. This could allow an attacker that has access to the network to perform a MITM attack in order to obtain the user´s credentials.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	6.3 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-287, CWE-295
Published	2022-09-23
Last modified	2026-06-17

Publisher (CNA): Spanish National Cybersecurity Institute, S.A. (INCIBE) · Vendor: velneo

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

Am I affected?

Timeline

2022-09-23 16:15 UTCPublished CVE record published
2026-06-17 04:13 UTCUpdated Record last modified

velneo vclient DOWNGRADE

Affected: 28.1.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 28.1.3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 28.1.3 (Debian / Ubuntu)

apt-cache madison vclient sudo apt install vclient=<VERSION_BEFORE_28.1.3> sudo apt-mark hold vclient

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

dnf --showduplicates list vclient sudo dnf downgrade vclient-<VERSION_BEFORE_28.1.3> sudo dnf versionlock add vclient

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-2021-45035?

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

Is CVE-2021-45035 being exploited?

CVE-2021-45035 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-2021-45035 affect?

CVE-2021-45035 affects vclient. Severity is medium (CVSS 6.3). Velneo vClient on its 28.1.3 version, does not correctly check the certificate of authenticity by default. This could allow an attacker that has access to the network to perform a MITM attack in order to obtain the user´s credentials.

How urgent is CVE-2021-45035?

Priority 32/100. No elevated risk signals yet.

Related CVEs

CVE-2021-45036 HIGH 8.7 DOWNGRADE Velneo vClient on its 28.1.3 version, could allow an attacker with knowledge of the victims's username and has

References

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