What’s Vulnerable › Vulnerabilities
CVE-2020-27121: Cisco Unified Communications Manager IM and Presence Service Denial of Service Vulnerability
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2020-11-06 · updated 2026-06-17
- Weakness: CWE-248
Description
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.
Affected products
References
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-imp-dos-uTx2dqu2
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-imp-dos-uTx2dqu2
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