dbcve.org
Cloud AgentApplication · Qualys

CVE-2023-28140

HIGH · 7.0 CVSS v3.1 Published 2023-04-18
Fix available
A fix is available. Upgrade to 4.5.3.1 or later.
See remediation →
73/100
Remediation priority · Elevated
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An Executable Hijacking condition exists in the Qualys Cloud Agent for Windows platform in versions before 4.5.3.1. Attackers may load a malicious copy of a Dependency Link Library (DLL) via a local attack vector instead of the DLL that the application was expecting, when processes are running with escalated privileges. This vulnerability is bounded only to the time of uninstallation and can only be exploited locally. At the time of this disclosure, versions before 4.0 are classified as End of Life.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A DLL search order hijacking vulnerability in Qualys Cloud Agent for Windows allows local attackers with escalated privileges to place a malicious DLL that gets loaded instead of the legitimate library during the uninstallation process. The attacker exploits the application's insecure DLL loading mechanism during the brief uninstallation window.

MitigationUpgrade Qualys Cloud Agent to version 4.5.3.1 or later to obtain the vendor patch. No workarounds are available for this code-level vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Cloud AgentApplication
Affected:>= 3.1.3.34, < 4.5.3.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
High
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Qualys Cloud Agent is installed
    Check for Qualys Cloud Agent in Windows Programs and Features (appwiz.cpl) or use PowerShell: Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -like '*Qualys*Cloud*Agent*'}
    Affected if The product is not found on the system, then this CVE does not apply
  2. Determine installed version number
    In Programs and Features, find the Qualys Cloud Agent entry and note the version column. Alternatively, check the executable version: Right-click C:\Program Files\Qualys\QualysCloudAgent\QualysCloudAgent.exe (or similar path) and view Properties > Details
    Affected if Cannot determine version - assume potentially affected if product is present
  3. Compare version to affected range
    The affected range is version >= 3.1.3.34 AND < 4.5.3.1. Compare your installed version to this range. For example, version 3.1.3.34 is affected, version 4.5.3.1 is NOT affected, version 4.0.0.0 IS affected
    Affected if Installed version is 3.1.3.34 or higher, but lower than 4.5.3.1 - the system is within the vulnerable version range
  4. Assess attack surface
    This vulnerability requires an attacker with local access and elevated (administrator) privileges to place a malicious DLL before uninstallation. Review local user accounts and administrator access on the system
    Affected if Multiple untrusted users with administrator privileges exist, increasing the likelihood of exploitation

If Qualys Cloud Agent is installed and the version falls between 3.1.3.34 (inclusive) and 4.5.3.1 (exclusive), the environment is affected by this vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.5.3.1 or later
Fixed in 4.5.3.1
Interim mitigation

Upgrade Qualys Cloud Agent to version 4.5.3.1 or later to obtain the vendor patch. No workarounds are available for this code-level vulnerability.

Recommended fix High confidence

4.5.3.1 or later

  1. 1. Backup current Qualys Cloud Agent configuration and any custom policies
  2. 2. Download Qualys Cloud Agent version 4.5.3.1 or later from the Qualys support portal
  3. 3. Stop all running Qualys Cloud Agent services via Windows Services console or command: net stop QualysAgent
  4. 4. Uninstall the current vulnerable version via Windows Add/Remove Programs or command line
  5. 5. Clear any remaining Qualys installation directories (typically C:\Program Files\Qualys\ or C:\Program Files (x86)\Qualys\)
  6. 6. Install the downloaded fixed version (4.5.3.1 or later) following Qualys installation documentation
  7. 7. Restart the Qualys Cloud Agent service: net start QualysAgent
  8. 8. Verify the installed version matches the fixed release using: qualys-cloud-agent.exe --version or via the agent UI
Caveat Ensure compatibility with your current Qualys subscription and platform requirements; older agent versions (pre-4.0) are End of Life per vendor

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Cloud Agent Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-28140 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-28140 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data