Anti Virus For Linux ServerApplication · Kaspersky

CVE-2017-9811

CRITICAL · 9.8 CVSS v3.0 Published 2017-07-17
Fix available
A fix is available. Upgrade to after 8.0.3.297 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

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
The kluser is able to interact with the kav4fs-control binary in Kaspersky Anti-Virus for Linux File Server before Maintenance Pack 2 Critical Fix 4 (version 8.0.4.312). By abusing the quarantine read and write operations, it is possible to elevate the privileges to root.

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
How this class of weakness works · CWE-20

The application accepts input without confirming it is well-formed or within expected bounds, so malformed data can push the program into states its author never anticipated. Attackers probe these gaps to trigger crashes, bypass logic, or feed tainted values into more dangerous operations downstream. Remediating it well means validating and normalising every input at the boundary against a strict allow-list — not merely filtering known-bad values.

General guidance for the improper input validation class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
Anti Virus For Linux ServerApplication
Affected:<= 8.0.3.297

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 a release after 8.0.3.297
Recommended fix High confidence

8.0.4.312 (Maintenance Pack 2 Critical Fix 4) or later

  1. Back up the current Kaspersky Anti-Virus for Linux configuration and quarantine data
  2. Stop the Kaspersky AV service using: systemctl stop kav4fs or service kav4fs stop
  3. Download Kaspersky Anti-Virus for Linux File Server version 8.0.4.312 (Maintenance Pack 2 Critical Fix 4) or later from the official Kaspersky download center
  4. Install the upgrade package using the appropriate method for your distribution (e.g., dpkg -i or rpm -ivh)
  5. Verify the installed version matches the fixed release: kav4fs-control --version
  6. Start the Kaspersky AV service: systemctl start kav4fs or service kav4fs start
  7. Confirm the service is running properly and quarantine functionality is operational
Caveat Test the upgrade in a non-production environment first as security software updates may affect system performance or compatibility with other software

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

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $2,300. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2017-9811 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2017-9811 in production — separate from our analysis above.

No notes yet

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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