CVE-2023-20259

A vulnerability in an API endpoint of multiple Cisco Unified Communications Products could allow an unauthenticated, remote attacker to cause high CPU utilization, which could impact access to the web-based management interface and cause delays with call processing. This API is not used for device management and is unlikely to be used in normal operations of the device. This vulnerability is due to improper API authentication and incomplete validation of the API request. An attacker could exploit this vulnerability by sending a crafted HTTP request to a specific API on the device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to high CPU utilization, which could negatively impact user traffic and management access. When the attack stops, the device will recover without manual intervention.

Published: 2023-10-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-20259 is rated Moderate Risk (47.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.17%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-20259

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-29 0.14% 0.17% +0.02%
2 2025-07-27 0.19% 0.14% -0.04%
3 2025-07-01 — 0.19% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-20259

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 4.0 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-20259

Affected software / configurations for CVE-2023-20259

Vendor Product Version Raw CPE
cisco emergency_responder 14su3 cpe:2.3:a:cisco:emergency_responder:14su3:*:*:*:*:*:*:*
cisco prime_collaboration_deployment 14su3 cpe:2.3:a:cisco:prime_collaboration_deployment:14su3:*:*:*:*:*:*:*
cisco unified_communications_manager 12.5\(1\)su7 cpe:2.3:a:cisco:unified_communications_manager:12.5\(1\)su7:*:*:*:*:*:*:*
cisco unified_communications_manager 12.5\(1\)su7 cpe:2.3:a:cisco:unified_communications_manager:12.5\(1\)su7:*:*:*:session_management:*:*:*
cisco unified_communications_manager 14su3 cpe:2.3:a:cisco:unified_communications_manager:14su3:*:*:*:*:*:*:*
cisco unified_communications_manager 14su3 cpe:2.3:a:cisco:unified_communications_manager:14su3:*:*:*:session_management:*:*:*
cisco unified_communications_manager_im_\&_presence_service 12.5\(1\)su7 cpe:2.3:a:cisco:unified_communications_manager_im_\&_presence_service:12.5\(1\)su7:*:*:*:*:*:*:*
cisco unified_communications_manager_im_\&_presence_service 14su3 cpe:2.3:a:cisco:unified_communications_manager_im_\&_presence_service:14su3:*:*:*:*:*:*:*
cisco unity_connection 14su3 cpe:2.3:a:cisco:unity_connection:14su3:*:*:*:*:*:*:*

References for CVE-2023-20259

cvelogic Threat Intelligence