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CVE Record

CVE-2021-45035: Velneo vClient Improper authentication

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.

MediumCVSS 6.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Velneo vClient 28.1.3 may fail to verify a server certificate correctly by default. A network-positioned attacker could impersonate the service connection and capture user credentials. The issue is not listed as CISA KEV, and the provided sources do not show active exploitation.

Executive priority

Treat this as a moderate credential-theft risk. It deserves timely remediation where Velneo vClient is used on shared or interceptable networks, but the provided evidence does not support emergency active-exploitation handling.

Technical view

CVE-2021-45035 is an improper authentication issue in Velneo vClient 28.1.3. The CVSS 3.1 vector requires adjacent network access and user interaction, with high confidentiality impact and low integrity impact. The weakness is mapped to CWE-287.

Likely exposure

Exposure is most likely where Velneo vClient 28.1.3 is still installed and users connect over networks where an attacker could intercept traffic, such as shared LANs, Wi-Fi, or poorly segmented internal networks.

Exploitation context

The source bundle describes a potential MITM scenario to obtain credentials. KEV is false, and no cited source in the bundle confirms active exploitation or public weaponization.

Researcher notes

The evidence names only Velneo vClient 28.1.3. Do not broaden scope without vendor confirmation. The most important validation points are version presence, certificate verification behavior, and whether an attacker could realistically gain network position.

Mitigation direction

  • Identify and prioritize any Velneo vClient 28.1.3 installations.
  • Review Velneo and INCIBE guidance for the vendor-supported fix or configuration change.
  • Check Velneo certificate verification documentation before relying on defaults.
  • Move users to a supported Velneo vClient release if vendor guidance recommends it.
  • Reduce exposure on untrusted or shared networks until remediated.

Validation and detection

  • Inventory endpoint software versions for Velneo vClient 28.1.3.
  • Verify certificate authenticity checking is enabled per Velneo documentation.
  • Confirm users do not connect from untrusted networks while remediation is pending.
  • Review authentication logs for suspicious credential use after network exposure.
  • Document affected systems, remediation status, and residual network risk.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-287: Credential and account abuse lookup

Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-45035 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.3CVSS 3.1MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N2.14.2Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.3Medium
CVSS 3.1 vector shape for CVE-2021-45035Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
VelneoVelneo vClient28.1.3Listed
Weakness

CWE details

CWE-287

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-287 · source CWE mapping

Improper Authentication

Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs