CyberSecBulletin
CVE-2017-8464Exploited in the wildNVD status: Analyzed

Microsoft Windows Shell (.lnk) Remote Code Execution

Published Updated By the CyberSecBulletin desk

CVE-2017-8464 is a high-severity vulnerability in Windows Shell from Microsoft, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. CISA added it to the Known Exploited Vulnerabilities catalogue on February 10, 2022, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Check which version of Windows Shell you run against the affected versions below, and install the vendor's latest release.
  2. CISA's required action: Apply updates per vendor instructions.
  3. Read the advisory on portal.msrc.microsoft.com for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  5. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
MicrosoftWindows ShellNot specified in the recordNot stated
MicrosoftWindows 10 1511Not specified in the recordNot stated
MicrosoftWindows 10 1607Not specified in the recordNot stated
MicrosoftWindows 10 1703Not specified in the recordNot stated
MicrosoftWindows 7Not specified in the recordNot stated
MicrosoftWindows 8.1Not specified in the recordNot stated
MicrosoftWindows Rt 8.1Not specified in the recordNot stated
MicrosoftWindows Server 2008r2Not stated
MicrosoftWindows Server 2012r2Not stated
MicrosoftWindows Server 2016Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighNVD
CVSS 3.18.8HighCISA (ADP)
CVSS 2.09.3HighNVD

Official description

Windows Shell in Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allows local users or remote attackers to execute arbitrary code via a crafted .LNK file, which is not properly handled during icon display in Windows Explorer or any other application that parses the icon of the shortcut. aka "LNK Remote Code Execution Vulnerability."

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Technical write-ups (may include proof of concept)

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