CVE-2019-1721

mediumpriority · track · 27EPSS 0.020 · 81 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.03% (81st) EPSS

CVSS 6.8 · medium

Is it mine?

22 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the phone book feature of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to cause the CPU to increase to 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to improper handling of the XML input. An attacker could exploit this vulnerability by sending a Session Initiation Protocol (SIP) message with a crafted XML payload to an affected device. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition. Manual intervention may be required to recover the device. This vulnerability is fixed in Cisco Expressway Series and Cisco TelePresence Video Communication Server Releases X12.5.1 and later.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco Expresswaycisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco TelePresence Video Communication Server (VCS)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

7.7

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6–7.7

v2.06.8mediumAV:N/AC:L/Au:S/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 8 · impact 6.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.07.7highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU

v3.07.7highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.1 · impact 4

v3.07.7highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US

v3.17.7highAV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20US

affected products (22)

Products and version ranges known to be affected.

showing 20 of 22

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-20190417-es-tvcs-dosCisco Expressway Series and Cisco TelePresence Video Communication Server Denial of Service Vulnerability2019-04-17csaf · cisco_csafUS
A vulnerability in the phone book feature of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to cause the CPU to increase to 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to improper handling of the XML input. An attacker could exploit this vulnerability by sending a Session Initiation Protocol (SIP) message with a crafted XML payload to an affected device. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition. Manual intervention may be required to recover the device. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Mitigation options that address this vulnerability are available. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-es-tvcs-dos ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-es-tvcs-dos"]

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf NVD CVE.org MITRE

published 2019-04-18modified 2026-06-17

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+25171 more

references (11)

External citations — patches, advisories, analysis.

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