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Fencer Vulns
high 7.5

CVE-2023-20108 json

A vulnerability in the XCP Authentication Service of the Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&…

published 2023-06-28 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-24287

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

A vulnerability in the XCP Authentication Service of the Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) could allow an unauthenticated, remote attacker to cause a temporary service outage for all Cisco Unified CM IM&P users who are attempting to authenticate to the service, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted login message to the affected device. A successful exploit could allow the attacker to cause an unexpected restart of the authentication service, preventing new users from successfully authenticating. Exploitation of this vulnerability does not impact Cisco Unified CM IM&P users who were authenticated prior to an attack.

Exploit prediction

0.93% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Cisco Cisco Unified Communications Manager IM and Presence Service

Classification

Weakness
  • CWE-789 Memory Allocation with Excessive Size Value
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.