Cyber Resilience

CVE-2021-47878

HighPublic PoC

Published: 21 January 2026

Published
21 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 0.0013 2.7th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2021-47878 is a high-severity Unquoted Search Path or Element (CWE-428) vulnerability in Server Web (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 2.7th 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 CM-6 (Configuration Settings) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2021-47878 is an unquoted service path vulnerability in the eBeam Device Service component of eBeam Education Suite version 2.5.0.9. This issue, mapped to CWE-428, stems from an improperly quoted executable path in the service configuration, enabling local users to potentially execute arbitrary code with elevated privileges. The vulnerability carries 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) and was published on 2026-01-21.

A local attacker with low privileges can exploit this vulnerability by placing a malicious executable in a directory that precedes the legitimate service binary in the system's path search order. During service startup, the Windows service control manager would execute the attacker's binary instead, running it with LocalSystem privileges and granting high confidentiality, integrity, and availability impacts, potentially leading to full system compromise.

Relevant resources include an exploit published on Exploit-DB at https://www.exploit-db.com/exploits/49647, a VulnCheck advisory at https://www.vulncheck.com/advisories/ebeam-education-suite-ebeam-device-service-unquoted-service-path, and the vendor's download page at http://esvc000385.wic045u.server-web.com/Downloads/eBeam/. Security practitioners should review these for mitigation guidance, such as applying patches if available or implementing service path hardening.

EU & UK References

Vulnerability details

eBeam Education Suite 2.5.0.9 contains an unquoted service path vulnerability in the eBeam Device Service that allows local users to potentially execute code with elevated privileges. Attackers can exploit the unquoted path in the service configuration to inject malicious code…

more

that would execute with LocalSystem privileges during service startup.

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?

Unquoted service path (CWE-428) directly enables path interception by placing a malicious binary earlier in the search order, executed at service startup with LocalSystem privileges.

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

Server Web
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly remediates the unquoted service path flaw in the eBeam Device Service through patching or corrective action to prevent privilege escalation.

prevent

Enforces secure configuration settings for Windows services, requiring properly quoted executable paths to block path hijacking exploits.

prevent

Mitigates impact of service hijacking by restricting service accounts to least privilege instead of LocalSystem, limiting potential damage from elevated code execution.

References