CVE-2020-27121 json
Cisco Unified Communications Manager IM and Presence Service Denial of Service Vulnerability
published 2020-11-06 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19645
- cvss
- 4.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 67%
- public exploits
- 0
- none known
Summary
A vulnerability in Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) Software could allow an authenticated, remote attacker to cause the Cisco XCP Authentication Service on an affected device to restart, resulting in a denial of service (DoS) condition. The vulnerability is due to improper handling of login requests. An attacker could exploit this vulnerability by sending a crafted client login request to an affected device. A successful exploit could allow the attacker to cause a process to crash, resulting in a DoS condition for new login attempts. Users who are authenticated at the time of the attack would not be affected. There are workarounds that address this vulnerability.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
1.16% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:N/I:N/A:P |
Affected products
- Cisco Cisco Unified Communications Manager IM and Presence Service
Classification
References
Sources
- CVE List CVE-2020-27121
- NVD CVE-2020-27121
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