CVE-2026-67303
When serial device redirection is enabled and a server-controlled IRP_MJ_DEVICE_CONTROL request specifies an unsupported IOCTL with a non-zero OutputBufferLength, CommDeviceIoControl() can fail with BytesReturned = 0, causing the mismatch to trigger the…
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
Description
FreeRDP before 3.29.0 contains a reachable assertion (WINPR_ASSERT(OutputBufferLength == BytesReturned)) in serial_process_irp_device_control() in channels/serial/client/serial_main.c. When serial device redirection is enabled and a server-controlled IRP_MJ_DEVICE_CONTROL request specifies an unsupported IOCTL with a non-zero OutputBufferLength, CommDeviceIoControl() can fail with BytesReturned = 0, causing the mismatch to trigger the assertion and abort the client process (denial of service).
- CVSS 4.0
- 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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/M
- EPSS
- 0.24% probability · 16th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-617
- Source
- disclosure@vulncheck.com
References
- https://github.com/FreeRDP/FreeRDP/commit/1cc783d4c78bd2f66d3a8582dfe70a663d141444
- https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493f
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-pfxq-3qmw-8vjx
- https://www.vulncheck.com/advisories/freerdp-before-denial-of-service-via-serial-devicecontrol
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.