CVE-2026-40254

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Versions prior to 3.25.0 have an off-by-one in the path traversal filter in channels/drive/client/drive_file.c. The contains_dotdot() function catches ../ and ..\ mid-path but misses .. when it's the last component with no trailing separator. A rogue RDP server can read, list, or write files one directory above the client's shared folder through RDPDR requests. This requires the victim to connect with drive redirection enabled. Version 3.25.0 patches the issue.

Affected Software

VendorProductVersion RangeStatus
FreeRDPFreeRDP< 3.25.0affected

Weaknesses

  • CWE-193: CWE-193: Off-by-one Error

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

References