Security readout for executives and security teams
Plain-English summary
CVE-2021-41160 affects FreeRDP clients before 2.4.1. A malicious or compromised RDP server can send malformed graphics updates that make the client write outside allocated memory. The main business risk is integrity impact on endpoints using vulnerable FreeRDP to connect to RDP servers.
Executive priority
Treat as a targeted client-side risk, not an internet-facing server emergency. Prioritize patching systems that use FreeRDP for administration, remote support, or connections to third-party RDP environments.
Technical view
FreeRDP lacks sufficient region bounds checks for GDI or SurfaceCommands graphics updates. Zero width or height and out-of-bounds rectangles can lead to zero allocation followed by out-of-bounds writes. The issue is CWE-787 and is patched in FreeRDP 2.4.1.
Likely exposure
Exposure is most likely on Linux or Unix-like endpoints, jump hosts, or automation environments running FreeRDP versions earlier than 2.4.1. Risk increases when users connect to untrusted, attacker-controlled, or compromised RDP servers.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not marked KEV. Exploitation requires a malicious server interacting with a vulnerable FreeRDP client and sending malformed graphics update data.
Researcher notes
Focus validation on FreeRDP client code paths handling GDI and SurfaceCommands graphics updates. The advisory describes missing bounds checks around zero-size and out-of-bounds rectangles. Do not assume code execution from the provided sources; they support out-of-bounds write and integrity impact.
Mitigation direction
- Upgrade FreeRDP to 2.4.1 or a distro package containing the fix.
- Apply relevant Fedora, Gentoo, Debian, or vendor security updates.
- Avoid using vulnerable FreeRDP clients with untrusted RDP servers.
- Remove or disable FreeRDP clients where no business need exists.
- Check current vendor guidance for supported fixed package versions.
Validation and detection
- Inventory systems with FreeRDP or freerdp2 installed.
- Confirm installed versions are 2.4.1 or vendor-fixed builds.
- Review whether users connect to external or untrusted RDP servers.
- Check package update history for relevant security advisories.
- Validate vulnerability scanner findings against package backport notes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-41160 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N0.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7c9r-6r2q-93qgCVE reference
- FEDORA-2021-2c25f03d0bCVE reference · vendor-advisory
- FEDORA-2021-5d227916bcCVE reference · vendor-advisory
- FEDORA-2021-ac23d9e47fCVE reference · vendor-advisory
- GLSA-202210-24CVE reference · vendor-advisory
- [debian-lts-announce] 20231117 [SECURITY] [DLA 3654-1] freerdp2 security updateCVE reference · mailing-list
- https://lists.debian.org/debian-lts-announce/2025/02/msg00016.htmlCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.