Microsoft UFO: Arbitrary file write in the Linux MCP `execute_command` tool
Microsoft UFO is an open-source framework for intelligent automation across devices and platforms. Prior to 3.0.9, the execute_command tool in ufo/client/mcp/http_servers/linux_mcp_server.py treats sort and uniq as read-only commands while the free-form command parameter can select their file-output forms. An authenticated caller can use sort -o or the optional second uniq operand to create or overwrite files writable by the UFO server process without shell metacharacters, because the allowed binary opens the destination itself and the argument policy does not reject the operation. This can corrupt configuration or other writable data and disrupt the service, but the demonstrated primitive does not directly disclose files or establish arbitrary code execution. This issue is fixed in version 3.0.9.
CVE-2026-105789
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-105789
UFO
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "microsoft",
"product": "UFO",
"versions": [
{
"status": "affected",
"version": "< 3.0.9"
}
]
}
]- Related CVEs
- CVE-2026-105789
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #9330 · Revision 1
- Added to Heist Feed
- Publisher date