Cyber Resilience

CVE-2021-47801

HighPublic PoC

Published: 16 January 2026

Published
16 January 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/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 0.0035 26.7th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2021-47801 is a high-severity SQL Injection (CWE-89) vulnerability in Vianeos OctoPUS (inferred from references). Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 26.7th 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 SI-10 (Information Input Validation) and SI-4 (System Monitoring).

Deeper analysis

CVE-2021-47801 is a time-based blind SQL injection vulnerability (CWE-89) in Vianeos OctoPUS 5, affecting the 'login_user' parameter during authentication requests. Attackers can exploit it by crafting malicious POST requests with specially constructed SQL payloads that trigger database sleep functions to extract information. The vulnerability carries a CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N) and was published on 2026-01-16.

Unauthenticated remote attackers can exploit this vulnerability over the network with low complexity and no user interaction required. By sending tailored POST requests to the authentication endpoint, they can infer database contents through timing differences caused by sleep functions, achieving high-impact confidentiality breaches with low integrity impact and no availability disruption.

Mitigation details are covered in advisories such as the VulnCheck advisory at https://www.vulncheck.com/advisories/vianeos-octopus-loginuser-sqli, with a public proof-of-concept exploit available at https://www.exploit-db.com/exploits/50078. Vendor product information is provided at https://vianeos.com/en/products/octopus and http://www.vianeos.com/en/home-vianeos/.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Vianeos OctoPUS 5 contains a time-based blind SQL injection vulnerability in the 'login_user' parameter during authentication requests. Attackers can exploit this vulnerability by crafting malicious POST requests with specially constructed SQL payloads that trigger database sleep functions to extract information.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Direct unauthenticated remote exploitation of a public-facing web application via SQL injection on the login endpoint.

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

CVEs Like This One

CVE-2026-24956Shared CWE-89
CVE-2026-33615Shared CWE-89
CVE-2025-28939Shared CWE-89
CVE-2021-47872Shared CWE-89
CVE-2025-28873Shared CWE-89
CVE-2019-25636Shared CWE-89
CVE-2026-32611Shared CWE-89
CVE-2026-42755Shared CWE-89
CVE-2024-53544Shared CWE-89
CVE-2026-21410Shared CWE-89

Affected Assets

Vianeos
OctoPUS
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 prevents time-based blind SQL injection by validating the 'login_user' parameter against malicious SQL payloads before database processing.

prevent

Enforces restrictions on input format, length, and characters for the authentication parameter to block SQL sleep functions and payloads.

detect

Enables monitoring of authentication requests for anomalous patterns like repeated timing delays indicative of time-based SQLi exploitation.

References