Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint rather than the actual StubLength about to be written. A malicious TS Gateway can send a PTYPE_RESPONSE with a small alloc_hint and a much larger frag_length, causing Stream_Write to copy attacker-controlled stub data beyond the 4096-byte pdu->s buffer. This can crash the client and may permit code execution through heap corruption. This issue is fixed in version 3.27.0.
Affected products
freerdp: freerdp
References4
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f… ExploitMitigationVendor Advisory
- github.com/FreeRDP/FreeRDP/commit/9f2da52c2341cc14a96ad12e69c5b… Patch
- github.com/FreeRDP/FreeRDP/pull/12873 Issue TrackingPatch
- github.com/FreeRDP/FreeRDP/releases/tag/3.27.0 Release Notes
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
8.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 50 · as of 10 November 2026
- CWE
- CWE-122
Could this be exploited in your environment?
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