VIR Vulnerability Intelligence Relay

CVE-2020-15261

unknown
Published — · Modified —
💬 Discuss on Community ✚ Propose mitigation
CVSS v3
—
CVSS v4 NEW
—
not yet in upstream
VIR risk
1.0

Description

On Windows the Veyon Service before version 4.4.2 contains an unquoted service path vulnerability, allowing locally authenticated users with administrative privileges to run malicious executables with LocalSystem privileges. Since Veyon users (both students and teachers) usually don't have administrative privileges, this vulnerability is only dangerous in anyway unsafe setups. The problem has been fixed in version 4.4.2. As a workaround, the exploitation of the vulnerability can be prevented by revoking administrative privileges from all potentially untrustworthy users.

Predictions

Exploit likelihood
20%
Patch ETA
—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-49925 local windows text · 2 KB
Víctor García · 2021-06-01

Veyon 4.4.1 - 'VeyonService' Unquoted Service Path

text exploit Source: Exploit-DB 
# Exploit Title: Veyon 4.4.1 - 'VeyonService' Unquoted Service Path
# Discovery by: Víctor García
# Discovery Date: 2020-03-23
# Vendor Homepage: https://veyon.io/
# Software Link: https://github.com/veyon/veyon/releases/download/v4.4.1/veyon-4.4.1.0-win64-setup.exe
# Tested Version: 4.4.1
# Vulnerability Type: Unquoted Service Path
# Tested on: Windows 10 Pro x64
# CVE: CVE-2020-15261

# Step to discover Unquoted Service Path:

C:\>wmic service get name,displayname,pathname,startmode |findstr /i
"auto" |findstr /i /v "C:\Windows\\" |findstr /i /v """
Veyon Service     VeyonService     C:\Program Files\Veyon\veyon-service.exe


# Service info:

C:\>sc qc VeyonService
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: VeyonService
        TYPE               : 10  WIN32_OWN_PROCESS
        START_TYPE         : 2   AUTO_START
        ERROR_CONTROL      : 1   NORMAL
        BINARY_PATH_NAME   : C:\Program Files\Veyon\veyon-service.exe
        LOAD_ORDER_GROUP   :
        TAG                : 0
        DISPLAY_NAME       : Veyon Service
        DEPENDENCIES       : Tcpip
                           : RpcSs
        SERVICE_START_NAME : LocalSystem


# Exploit:

# A successful attempt would require the local user to be able to insert their code in the
# system root path undetected by the OS or other security applications where it could
# potentially be executed during application startup or reboot. If successful, the local
# user's code would execute with the elevated privileges of the application.

OS impact
debian Debian Fixed 5 releases
VersionStatusFixed in
trixie Fixed 0
sid Fixed 0
forky Fixed 0
bullseye Fixed 0
bookworm Fixed 0

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.