CyberSecBulletin
CVE-2023-47267NVD status: Analyzed

Thegreenbow VPN Client: Improper Privilege Management

Published Updated By the CyberSecBulletin desk

CVE-2023-47267 is a critical-severity improper privilege management vulnerability in Thegreenbow VPN Client from TheGreenBow, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 6.52.006, 6.87.108, 6.87.109 as the first without the flaw, so updating Thegreenbow VPN Client to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.75% chance of exploitation within 30 days, higher than 56% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Thegreenbow VPN Client to 6.52.006 or 6.87.108 or 6.87.109, whichever matches your release line, or a later version.
  2. Read the advisory on thegreenbow.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
ThegreenbowThegreenbow VPN Client6.52.004 up to, but not including, 6.52.006; 6.87.001 up to, but not including, 6.87.108; 6.87.001 up to, but not including, 6.87.1096.52.006, 6.87.108, 6.87.109

Version data comes from NVD's product matching. 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
NoneNo action by a victim is required.
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:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

An issue discovered in TheGreenBow Windows Enterprise Certified VPN Client 6.52, Windows Standard VPN Client 6.87, and Windows Enterprise VPN Client 6.87 allows attackers to gain escalated privileges via crafted changes to memory mapped file.

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

The underlying weakness: Improper Privilege Management

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.

More Improper Privilege Management vulnerabilities (CWE-269)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Improper Privilege Management vulnerabilities

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