Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-20238 is a critical-severity Improper Authentication (CWE-287) vulnerability in Cisco Broadworks Xtended Services Platform. Its CVSS base score is 10.0 (Critical).
Operationally, ranked in the top 3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A vulnerability in the single sign-on implementation of Cisco BroadWorks Application Delivery Platform and Cisco BroadWorks Xtended Services Platform allows an unauthenticated remote attacker to forge SSO credentials. The flaw stems from insufficient validation of SSO tokens (CWE-287) and carries a CVSS 3.1 score of 10.0. Successful exploitation requires only a valid user ID associated with an affected system.
An attacker can authenticate using forged credentials to gain access at the privilege level of the targeted account. This enables toll fraud, command execution, viewing of confidential information, or modification of customer and user settings when an administrator account is impersonated.
The Cisco Security Advisory cisco-sa-bw-auth-bypass-kCggMWhX provides official details on the issue. The EPSS score has reached a peak and current value of 0.4660.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-24417
Vulnerability Data
A vulnerability in the single sign-on (SSO) implementation of Cisco BroadWorks Application Delivery Platform and Cisco BroadWorks Xtended Services Platform could allow an unauthenticated, remote attacker to forge the credentials required to access an affected system. This vulnerability is due…
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to the method used to validate SSO tokens. An attacker could exploit this vulnerability by authenticating to the application with forged credentials. A successful exploit could allow the attacker to commit toll fraud or to execute commands at the privilege level of the forged account. If that account is an Administrator account, the attacker would have the ability to view confidential information, modify customer settings, or modify settings for other users. To exploit this vulnerability, the attacker would need a valid user ID that is associated with an affected Cisco BroadWorks system.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Detects unauthorized successful logons resulting from improper authentication implementations.
Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.
Security awareness training instructs users on secure authentication practices and avoiding credential compromise.
Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.
Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.
Session content review can reveal authentication bypasses or failures in session establishment.
Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Mandating segregated approval and oversight for non-human identities reduces the chance that weak or orphaned credentials can be exploited for unauthorized authentication.
A.5.17 directly mandates generation of non-guessable unique secrets, secure transmission, immediate change of defaults/temporary creds, strong password enforcement, no-reuse, and compromise response, which stops most improper-authentication exploits at source; the bounded remainder is non-password authentication methods and sufficiency-of-proof cases (e.g. IA-2/IA-5 enhancements) left to other controls.
Security requirements specified early and verified through testing drive the consistent implementation of authentication mechanisms, decreasing the likelihood that authentication steps are omitted or incorrectly applied.
A.8.26 explicitly requires identifying and addressing authentication-related requirements (including level of trust in identity via 8.5 and 5.17) as part of application development or acquisition, which prevents a slice of CWE-287 but leaves the dominant sufficiency-of-proof aspects (IA-2/IA-5) and many implementation defects untouched.
A.8.27 mandates security-by-design principles (least privilege, default-deny, never-trust/always-verify, MFA, end-to-end encryption of requests, distrust-external-input, secure session control, and explicit authentication/authorization in every layer), which directly stops most improper-authentication flaws from being exploitable; the bounded remainder is insufficient-proof cases that live only in the strength or correctness of the credential itself (IA-5/IA-2 territory).
A.8.5 directly mandates appropriate-strength authentication techniques, MFA for critical systems, protected log-on procedures, brute-force resistance, no cleartext passwords/transmission, and session controls that stop exploitation of insufficient proof of identity; the bounded remainder is cases where the chosen technique itself is flawed or insufficiently implemented (e.g. weak biometrics without fallback).
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.