CyberSecBulletin
CVE-2023-40181NVD status: Modified

FreeRDP: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2023-40181 is a critical-severity out-of-bounds read vulnerability in FreeRDP, 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. Affected FreeRDP versions: < 2.11.0; >= 3.0.0-beta1, < 3.0.0-beta3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.69% chance of exploitation within 30 days, higher than 78% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of FreeRDP you run against the affected versions below, and install the vendor's latest release.
  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< 2.11.0; >= 3.0.0-beta1, < 3.0.0-beta3Not stated
DebianDebian Linux10.0Not stated
Fedora ProjectFedora37; 38; 39Not 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
NoneNothing can be modified.
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:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.15.3MediumCNA (github.com)
CVSS 3.19.1CriticalNVD

Official description

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Integer-Underflow leading to Out-Of-Bound Read in the `zgfx_decompress_segment` function. In the context of `CopyMemory`, it's possible to read data beyond the transmitted packet range and likely cause a crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

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

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

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

References

Third-party and government advisories

Other vulnerabilities in FreeRDP

All FreeRDP vulnerabilities

Recent Out-of-bounds Read vulnerabilities

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