CVE-2023-39356
CVE-2023-39356 is a medium-severity vulnerability in Freerdp with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: Medium (CVSS 3.x base score 5.3)
- EPSS exploit prediction: 2% (72nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-125
- Affected product: Freerdp
- Published:
- Last modified:
Description
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions a missing offset validation may lead to an Out Of Bound Read in the function `gdi_multi_opaque_rect`. In particular there is no code to validate if the value `multi_opaque_rect->numRectangles` is less than 45. Looping through `multi_opaque_rect->`numRectangles without proper boundary checks can lead to Out-of-Bounds Read errors which will likely lead to 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 vulnerability.
Frequently asked questions
- What is CVE-2023-39356?
- FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions a missing offset validation may lead to an Out Of Bound Read in the function `gdi_multi_opaque_rect`. In particular there is no code to validate if the value `multi_opaque_rect->numRectangles` is less than 45. Looping through `multi_opaque_rect->`numRectangles without proper boundary checks can lead to Out-of-Bounds Read errors which will likely lead to 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 vulnerability.
- How severe is CVE-2023-39356?
- CVE-2023-39356 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
- Is CVE-2023-39356 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2023-39356?
- CVE-2023-39356 primarily affects Freerdp. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2023-39356?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2023-39356 published?
- CVE-2023-39356 was published on 2023-08-31 and last updated on 2026-06-17.
References
- https://github.com/FreeRDP/FreeRDP/blob/63a2f65618748c12f79ff7450d46c6e194f2db76/include/freerdp/primary.h#L186-L196
- https://github.com/FreeRDP/FreeRDP/blob/63a2f65618748c12f79ff7450d46c6e194f2db76/libfreerdp/core/orders.c#L1503-L1504
- https://github.com/FreeRDP/FreeRDP/blob/63a2f65618748c12f79ff7450d46c6e194f2db76/libfreerdp/gdi/gdi.c#L723C1-L758
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-q5v5-qhj5-mh6m
- https://lists.debian.org/debian-lts-announce/2023/10/msg00008.html
- https://lists.fedoraproject.org/archives/list/[email protected]/message/A6LLDAPEXRDJOM3PREDDD267SSNT77DP/
- https://lists.fedoraproject.org/archives/list/[email protected]/message/IHMTGKCZXJPQOR5ZD2I4GPDNP2DKRXMF/
- https://lists.fedoraproject.org/archives/list/[email protected]/message/OH2ATH2BKDNKCJAU4WPPXK4SHLE3UJUV/
- https://security.gentoo.org/glsa/202401-16
- https://lists.debian.org/debian-lts-announce/2025/02/msg00016.html
Affected products (7)
- cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*
- cpe:2.3:a:freerdp:freerdp:3.0.0:beta1:*:*:*:*:*:*
- cpe:2.3:a:freerdp:freerdp:3.0.0:beta2:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*
More vulnerabilities in Freerdp
- CVE-2026-45700 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, FreeRDP's planar bitmap decoder has…
- CVE-2026-31806 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function…
- CVE-2026-25997 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_clipboard_format_equal`…
- CVE-2026-25959 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_cliprdr_provide_data_`…
- CVE-2026-25955 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0,…
- CVE-2026-25953 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0,…
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