What’s Vulnerable › Vulnerabilities
CVE-2023-40181: Integer-Underflow leading to Out-Of-Bound Read in FreeRDP
- Severity: critical (CVSS 9.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.7% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2023-08-31 · updated 2026-06-17
- Weakness: CWE-125
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.
Affected products
- Debian Linux: 10.0
- Fedoraproject Fedora: 37, 38, 39
- FreeRDP: before 2.11.0; 3.0.0-beta1, 3.0.0-beta2 — fixed in 2.11.0
How to fix
Upgrade to a fixed version: FreeRDP 2.11.0. Check the vendor advisory for mitigations.
References
- https://github.com/FreeRDP/FreeRDP/blob/2252d53001d9ce8a452f0a0a5b1f5ed9db6d57f1/libfreerdp/codec/zgfx.c#L256-L261
- https://github.com/FreeRDP/FreeRDP/blob/2252d53001d9ce8a452f0a0a5b1f5ed9db6d57f1/libfreerdp/codec/zgfx.c#L334-L355
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mxp4-rx7x-h2g8
- https://lists.debian.org/debian-lts-announce/2023/10/msg00008.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A6LLDAPEXRDJOM3PREDDD267SSNT77DP/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IHMTGKCZXJPQOR5ZD2I4GPDNP2DKRXMF/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OH2ATH2BKDNKCJAU4WPPXK4SHLE3UJUV/
- https://security.gentoo.org/glsa/202401-16
- https://github.com/FreeRDP/FreeRDP/blob/2252d53001d9ce8a452f0a0a5b1f5ed9db6d57f1/libfreerdp/codec/zgfx.c#L256-L261
- https://github.com/FreeRDP/FreeRDP/blob/2252d53001d9ce8a452f0a0a5b1f5ed9db6d57f1/libfreerdp/codec/zgfx.c#L334-L355
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mxp4-rx7x-h2g8
- https://lists.debian.org/debian-lts-announce/2023/10/msg00008.html
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