OMENWAVE modelled vulnerability-chaining pathways

CVE-2023-20269

A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or an authenticated, remote attacker to establish a clientless SSL VPN session with an unauthorized user. This vulnerability is due to improper separation of authentication, authorization, and accounting (AAA) between the remote access VPN feature and the HTTPS management and site-to-site VPN features. An attacker could exploit this vulnerability by specifying a default connection profile/tunnel group while conducting a brute force attack or while establishing a clientless SSL VPN session using valid credentials. A successful exploit could allow the attacker to achieve one or both of the following: Identify valid credentials that could then be used to establish an unauthorized remote access VPN session. Establish a clientless SSL VPN session (only when running Cisco ASA Software Release 9.16 or earlier). Notes: Establishing a client-based remote access VPN tunnel is not possible as these default connection profiles/tunnel groups do not and cannot have an IP address pool configured. This vulnerability does not allow an attacker to bypass authentication. To successfully establish a remote access VPN session, valid credentials are required, including a valid second factor if multi-factor authentication (MFA) is configured. Cisco will release software updates that address this vulnerability. There are workarounds that address this vulnerability.

9.1
CVSS Critical
26.6%
EPSS p98
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
PRIV access
Capabilities
authentication bypassinformation disclosureprivilege gaindata tampering
Model confidence
high · CVSS 3.1
Top plausible next hops
CVE-2016-6366INITIAL_ACCESS → EXECUTIONhigh plausibility · KEV

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

Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Fi…

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…

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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-2023-20269