CyberSecBulletin
CVE-2024-32040NVD status: Modified

FreeRDP: Integer Underflow (Wrap or Wraparound)

Published Updated By the CyberSecBulletin desk

CVE-2024-32040 is a critical-severity integer underflow (wrap or wraparound) vulnerability in FreeRDP, 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 version 2.11.6 as the first without the flaw, so updating FreeRDP to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.91% chance of exploitation within 30 days, higher than 80% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update FreeRDP to 2.11.6 or a later version.
  2. Read the advisory on github.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
FreeRDPFreeRDP>= 3.0.0, 3.5.0; < 2.11.6; before 2.11.6; 3.0.0 through 3.5.02.11.6
Fedora ProjectFedora38; 39; 40Not 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
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.

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (github.com)
CVSS 3.19.8CriticalNVD

Official description

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients that use a version of FreeRDP prior to 3.5.0 or 2.11.6 and have connections to servers using the `NSC` codec are vulnerable to integer underflow. Versions 3.5.0 and 2.11.6 patch the issue. As a workaround, do not use the NSC codec (e.g. use `-nsc`).

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

The underlying weakness: Integer Underflow (Wrap or Wraparound)

The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

More Integer Underflow (Wrap or Wraparound) vulnerabilities (CWE-191)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in FreeRDP

All FreeRDP vulnerabilities

Recent Integer Underflow (Wrap or Wraparound) vulnerabilities

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