Cyber Resilience

CVE-2021-47803

HighPublic PoC

Published: 16 January 2026

Published
16 January 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 8.5 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/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 Score 0.0015 4.5th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2021-47803 is a high-severity Unquoted Search Path or Element (CWE-428) vulnerability in I Funbox (inferred from references). Its CVSS base score is 8.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception by Unquoted Path (T1574.009); ranked at the 4.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and CM-6 (Configuration Settings).

Deeper analysis

CVE-2021-47803 is an unquoted service path vulnerability affecting iFunbox version 4.2, specifically in the Apple Mobile Device Service. This flaw, classified under CWE-428, enables local attackers to execute arbitrary code with elevated privileges by placing a malicious executable in the unquoted service path. When the service restarts, the malicious binary runs with LocalSystem privileges. The vulnerability has a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high impact with low complexity and low privileges required.

Local low-privileged attackers can exploit this vulnerability to achieve privilege escalation on affected Windows systems running iFunbox 4.2. By identifying the unquoted path in the service configuration and replacing or inserting a malicious executable named to match the service's expected binary, the attacker gains LocalSystem-level access upon service restart. This provides full control over the system, including high confidentiality, integrity, and availability impacts.

Advisories and related resources, including those from VulnCheck and an Exploit-DB entry (exploit 50040), detail the issue and provide proof-of-concept exploitation. The iFunbox vendor website is referenced, though no specific patches or mitigations are outlined in the available information. Security practitioners should verify service paths, apply any vendor updates, and consider removing or restricting iFunbox usage on endpoints.

EU & UK References

Vulnerability details

iFunbox 4.2 contains an unquoted service path vulnerability in the Apple Mobile Device Service that allows local attackers to execute code with elevated privileges. Attackers can insert a malicious executable into the unquoted service path to run with LocalSystem privileges…

more

when the service restarts.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1574.009 Path Interception by Unquoted Path Stealth
Adversaries may execute their own malicious payloads by hijacking vulnerable file path references.
Why these techniques?

Direct unquoted service path in Windows service enables path interception for privilege escalation to LocalSystem.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2020-36928Shared CWE-428
CVE-2023-54336Shared CWE-428
CVE-2020-37048Shared CWE-428
CVE-2019-25306Shared CWE-428
CVE-2020-36979Shared CWE-428
CVE-2020-36929Shared CWE-428
CVE-2020-37017Shared CWE-428
CVE-2021-47859Shared CWE-428
CVE-2019-25309Shared CWE-428
CVE-2021-47790Shared CWE-428

Affected Assets

I Funbox
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

CM-6 enforces secure configuration settings for system services, directly preventing unquoted service path vulnerabilities by requiring properly quoted executable paths and protected directories.

prevent

SI-2 requires identification, scanning, and remediation of flaws like CVE-2021-47803, including unquoted service paths detected by vulnerability scanners.

prevent

AC-6 enforces least privilege for services, preventing LocalSystem privilege escalation by requiring services like Apple Mobile Device Service to run with minimal necessary privileges.

References