OMENWAVE modelled vulnerability-chaining pathways

CVE-2021-28799

An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If exploited, the vulnerability allows remote attackers to log in to a device. This issue affects: QNAP Systems Inc. HBS 3 versions prior to v16.0.0415 on QTS 4.5.2; versions prior to v3.0.210412 on QTS 4.3.6; versions prior to v3.0.210411 on QTS 4.3.4; versions prior to v3.0.210411 on QTS 4.3.3; versions prior to v16.0.0419 on QuTS hero h4.5.1; versions prior to v16.0.0419 on QuTScloud c4.5.1~c4.5.4. This issue does not affect: QNAP Systems Inc. HBS 2 . QNAP Systems Inc. HBS 1.3 .

9.8
CVSS Critical
78.2%
EPSS p100
YES
In CISA KEV
YES
Ransomware-linked

Data as of 2 Nov 2026 · NVD, CISA KEV, EPSS

Why chaining, at machine speed

Defenders still triage vulnerabilities one CVE at a time, while increasingly automated attackers combine them at machine speed. Omenwave models the plausible pathways by which this CVE could be chained with others — surfacing them for research and awareness, with evidence for each step.

Modelled capability profile
Kill-chain stage
INITIAL_ACCESS
Requires
NONE access, NETWORK vector
Grants
USER access
Capabilities
code execution
Model confidence
high · CVSS 3.1
Top plausible next hops
CVE-2025-49704INITIAL_ACCESS → EXECUTIONhigh plausibility · KEV

The access level the source grants already meets or exceeds the access level the destination requires — the position carries over.

Improper control of generation of code ('code injection') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

CVE-2022-41040INITIAL_ACCESS → EXECUTIONhigh plausibility · KEV

The access level the source grants already meets or exceeds the access level the destination requires — the position carries over.

Microsoft Exchange Server Elevation of Privilege Vulnerability

CVE-2020-0688INITIAL_ACCESS → EXECUTIONhigh plausibility · KEV

The access level the source grants already meets or exceeds the access level the destination requires — the position carries over.

A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Micros…

CVE-2025-49113INITIAL_ACCESS → EXECUTIONhigh plausibility · KEV

The access level the source grants already meets or exceeds the access level the destination requires — the position carries over.

Roundcube Webmail before 1.5.10 and 1.6.x before 1.6.11 allows remote code execution by authenticated users because the _from parameter in a URL is n…

CVE-2020-11978INITIAL_ACCESS → EXECUTIONhigh plausibility · KEV

The access level the source grants already meets or exceeds the access level the destination requires — the position carries over.

An issue was found in Apache Airflow versions 1.10.10 and below. A remote code/command injection vulnerability was discovered in one of the example D…

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Modelled plausible chaining potential derived from public CVE metadata (CVSS, CWE, CPE). Not a confirmed real-world exploit chain and contains no exploitation detail. For research and awareness only.

Methodology · Interactive explorer · JSON: /cve/CVE-2021-28799