Cyber Resilience

CVE-2023-20246

Auth Bypass in Snort 3.0.0 – 3.1.57.0

Published
01 November 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 5.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
EPSS Score 0.0056 43th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2023-20246 is a medium-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Snort Snort. Its CVSS base score is 5.8 (Medium).

Operationally, ranked at the 43th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Multiple Cisco products are affected by a vulnerability in Snort access control policies that could allow an unauthenticated, remote attacker to bypass the configured policies on an affected system. This vulnerability is due to a logic error that occurs when…

more

the access control policies are being populated. An attacker could exploit this vulnerability by establishing a connection to an affected device. A successful exploit could allow the attacker to bypass configured access control rules on the affected system.

CWE(s)

Related Threats

CVEs Like This One

CVE-2024-20384Same product: Cisco Firepower Threat Defense
CVE-2024-20297Same product: Cisco Firepower Threat Defense
CVE-2023-20245Same product: Cisco Firepower Threat Defense
CVE-2024-20299Same product: Cisco Firepower Threat Defense
CVE-2023-20256Same product: Cisco Firepower Threat Defense
CVE-2023-20071Same product: Cisco Firepower Threat Defense
CVE-2024-20363Same product: Cisco Firepower Threat Defense
CVE-2024-20437Same product: Cisco Ios Xe
CVE-2023-20031Same product: Cisco Firepower Threat Defense
CVE-2023-20070Same product: Cisco Firepower Threat Defense

Affected Assets

snort
snort
3.0.0 — 3.1.57.0
cisco
firepower threat defense
7.0.0 — 7.3.1.1
cisco
ios xe
17.12 — 17.12.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V10.4.16
  • V10.5.1
  • V11.4.3

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.

addresses: CWE-290

Reveals spoofed logon attempts through unexpected previous logon timestamps upon legitimate login.

addresses: CWE-290

Training specifically addresses recognizing spoofed communications and phishing that enable authentication bypass.

addresses: CWE-290

Requiring verifiable identity evidence at appropriate assurance levels makes it substantially harder for attackers to successfully spoof or impersonate users to obtain accounts.

addresses: CWE-290

Unique device authentication makes successful spoofing of device identity substantially more difficult to achieve.

addresses: CWE-290

Unique identification of non-organizational users reduces the feasibility of authentication bypass by spoofing.

addresses: CWE-290

Unique identification and authentication of services before communications makes spoofing of service identities substantially harder.

addresses: CWE-290

Isolated trusted path ensures the user interacts only with genuine system components, preventing spoofing of authentication interfaces or prompts.

addresses: CWE-290

Directly counters DNS response spoofing by requiring cryptographic origin authentication artifacts from the authoritative source.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-04 full match
prevents

Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.

PR.AA-03 mostly match
prevents

Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.

PR.AA-02 partial match
prevents

Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.

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.

degrades

Secure authentication control directly mitigates authentication bypass by spoofing.

degrades

Authentication information management directly addresses credential handling that prevents spoofing.

detects

Security testing can detect spoofing vulnerabilities but does not prevent them by itself.

prevents

Access control policy reduces spoofing opportunities but does not prescribe authentication mechanisms.

prevents

Identity management supports unique identities but does not guarantee resistance to spoofing.

prevents

Access rights assignment limits exposure but does not enforce authentication strength.

References