Cyber Resilience

CVE-2023-20018

Auth Bypass in Cisco Ip Phone 7800 Firmware ≤ 14.1\(1\)sr2

Published
20 January 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 8.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
EPSS Score 0.0061 46th percentile
Risk Priority 65 floored blend · peak EPSS

Summary

CVE-2023-20018 is a high-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Cisco Ip Phone 7800 Firmware. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 46th 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

A vulnerability in the web-based management interface of Cisco IP Phone 7800 and 8800 Series Phones could allow an unauthenticated, remote attacker to bypass authentication on an affected device. This vulnerability is due to insufficient validation of user-supplied input. An…

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attacker could exploit this vulnerability by sending a crafted request to the web-based management interface. A successful exploit could allow the attacker to access certain parts of the web interface that would normally require authentication.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
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.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1548.002 Bypass User Account Control Privilege Escalation
Adversaries may bypass UAC mechanisms to elevate process privileges on system.
T1548.003 Sudo and Sudo Caching Privilege Escalation
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20269Same vendor: Cisco
CVE-2020-3161Same product: Cisco Ip Phone 7811
CVE-2024-20537Same vendor: Cisco
CVE-2024-20510Same vendor: Cisco
CVE-2024-20482Same vendor: Cisco
CVE-2025-20257Same vendor: Cisco
CVE-2023-20078Same product: Cisco Ip Phone 7811
CVE-2023-20079Same product: Cisco Ip Phone 7811
CVE-2025-20350Same product: Cisco Ip Phone 7811
CVE-2023-20190Same vendor: Cisco

Affected Assets

cisco
ip phone 7800 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 7811 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 7821 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 7832 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 7841 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 7861 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 8800 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 8811 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 8821 firmware
≤ 14.1\(1\)sr2
cisco
ip phone 8821-ex firmware
≤ 14.1\(1\)sr2
+12 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 12 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V6.6.1
  • V12.1.3

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-288 CWE-863

Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.

addresses: CWE-863 CWE-288

Centralized authorization servers reduce incorrect authorization by enforcing consistent policies.

addresses: CWE-863

Periodic review and update of procedures reduces incorrect authorization implementations over time.

addresses: CWE-863

Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.

addresses: CWE-863

Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.

addresses: CWE-863

Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.

addresses: CWE-863

Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.

addresses: CWE-863

Monitoring account use, notifying on changes, and reviewing accounts for compliance corrects incorrect authorization assignments.

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-03 full match
prevents

Requiring authentication on every channel and path directly eliminates alternate-path bypasses.

PR.AA-05 mostly match
prevents

Enforcing authorizations and least privilege across all access vectors prevents unauthenticated alternate paths.

PR.IR-01 mostly match
prevents

Protecting networks and environments from unauthorized logical access blocks bypass via undocumented channels.

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.

finds

Security testing can detect alternate-path bypasses but does not prevent them in production.

degrades

Secure authentication control directly mitigates bypass by requiring strong, consistent authentication on all paths.

prevents

Access control policy directly addresses alternate authentication paths by requiring all channels to enforce authentication.

degrades

Authentication information management ensures credentials and mechanisms are consistently applied across all access paths.

prevents

Access rights provisioning and review prevent bypass via unmonitored or alternate channels.

prevents

Privileged access rights control reduces risk of bypass through elevated or alternate paths.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (4 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
  • V-248598 There must be no ".shosts" files on the OL 8 operating system. prevents CWE-288
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-288
Oracle Linux 9 (2 rules)
  • V-271757 OL 9 file systems must not contain shosts.equiv files. prevents CWE-288
  • V-271758 OL 9 file systems must not contain .shosts files. prevents CWE-288
RHEL 7 (4 rules)
  • V-204440 Red Hat Enterprise Linux operating systems version 7.2 or newer using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes. prevents CWE-288
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-288
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. prevents CWE-288
RHEL 8 (1 rule)
  • V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863

References