CyberSecBulletin
CVE-2024-5594NVD status: Modified

OpenVPN: Improper Validation of Specified Type of Input

Published Updated By the CyberSecBulletin desk

CVE-2024-5594 is a critical-severity improper validation of specified type of input vulnerability in OpenVPN, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.6.11 as the first without the flaw, so updating OpenVPN to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update OpenVPN to 2.6.11 or a later version.
  2. Read the advisory on community.openvpn.net 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
OpenVPNOpenVPNbefore 2.6.112.6.11

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
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
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CISA (ADP).

Official description

OpenVPN before 2.6.11 does not santize PUSH_REPLY messages properly which an attacker controlling the server can use to inject unexpected arbitrary data ending up in client logs.

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

The underlying weakness: Improper Validation of Specified Type of Input

The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.

More Improper Validation of Specified Type of Input vulnerabilities (CWE-1287)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in OpenVPN

All OpenVPN vulnerabilities

Recent Improper Validation of Specified Type of Input vulnerabilities

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