How severe is CVE-2024-20253?

CVE-2024-20253 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability high.

Is CVE-2024-20253 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-20253?

CVE-2024-20253 primarily affects Cisco Unified Communications Manager. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-20253?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2024-20253 have an EU (EUVD) identifier?

Yes. CVE-2024-20253 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-17968.

When was CVE-2024-20253 published?

CVE-2024-20253 was published on 2024-01-26 and last updated on 2026-06-17.

CVE-2024-20253

CVE-2024-20253 is a critical-severity vulnerability in Cisco Unified Communications Manager with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-17968
Weakness: CWE-502
Affected product: Cisco Unified Communications Manager
Published: 2024-01-26
Last modified: 2026-06-17

Description

A vulnerability in multiple Cisco Unified Communications and Contact Center Solutions products could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to the improper processing of user-provided data that is being read into memory. An attacker could exploit this vulnerability by sending a crafted message to a listening port of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of the web services user. With access to the underlying operating system, the attacker could also establish root access on the affected device.

Frequently asked questions

What is CVE-2024-20253?: A vulnerability in multiple Cisco Unified Communications and Contact Center Solutions products could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to the improper processing of user-provided data that is being read into memory. An attacker could exploit this vulnerability by sending a crafted message to a listening port of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of the web services user. With access to the underlying operating system, the attacker could also establish root access on the affected device.
How severe is CVE-2024-20253?: CVE-2024-20253 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability high.
Is CVE-2024-20253 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-20253?: CVE-2024-20253 primarily affects Cisco Unified Communications Manager. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-20253?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2024-20253 have an EU (EUVD) identifier?: Yes. CVE-2024-20253 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-17968.
When was CVE-2024-20253 published?: CVE-2024-20253 was published on 2024-01-26 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cucm-rce-bWNzQcUm

Affected products (9)

cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:session_management:*:*:*
cpe:2.3:a:cisco:unified_communications_manager_im_and_presence_service:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:unity_connection:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:unified_contact_center_express:12.5\(1\):-:*:*:*:*:*:*
cpe:2.3:a:cisco:virtualized_voice_browser:12.5\(1\):*:*:*:*:*:*:*
cpe:2.3:a:cisco:virtualized_voice_browser:12.6\(1\):*:*:*:*:*:*:*
cpe:2.3:a:cisco:virtualized_voice_browser:12.6\(2\):*:*:*:*:*:*:*

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