cbcvebase.
CVE-2019-1636
published 2019-01-23

CVE-2019-1636: A vulnerability in the Cisco Webex Teams client, formerly Cisco Spark, could allow an attacker to execute arbitrary commands on a targeted system. This…

PriorityP262high7.8CVSS 3.0
AVLACLPRNUIRSUCHIHAH
EXPLOIT
EPSS
46.89%
98.7th percentile
A vulnerability in the Cisco Webex Teams client, formerly Cisco Spark, could allow an attacker to execute arbitrary commands on a targeted system. This vulnerability is due to unsafe search paths used by the application URI that is defined in Windows operating systems. An attacker could exploit this vulnerability by convincing a targeted user to follow a malicious link. Successful exploitation could cause the application to load libraries from the directory targeted by the URI link. The attacker could use this behavior to execute arbitrary commands on the system with the privileges of the targeted user if the attacker can place a crafted library in a directory that is accessible to the vulnerable system.

Affected

3 ranges
VendorProductVersion rangeFixed in
ciscocisco_webex_teams
ciscowebex_teams
ciscowebex_teams_uri_handler

Detection & IOCsextracted from sources · hover to see the quote

filenameFILE1337.dll
pathimageformats
commandorigin://?" -platformpluginpath \\<share>\imageformats "
commandorigin://?" -reverse "
commandorigin://?" -Origin_MultipleInstances "
commandorigin://?" /noUpdate "
commandorigin://?" /StartClientMinimized /noUpdate -Origin_MultipleInstances "
  • Monitor for processes launched with Qt argument '-platformpluginpath' pointing to a UNC/remote Windows share path, which is the mechanism used to load a malicious DLL remotely.
  • Detect .URL shortcut files containing custom URI schemes (e.g., 'origin://') with injected arguments (special characters like '"', spaces, '-', '/') in the URL= field, as these bypass browser argument encoding protections.
  • Alert on DLL loads from UNC paths (\\server\share\...) by Webex Teams / Cisco Spark or other Qt-based application processes, indicating potential insecure library loading via URI handler.
  • Monitor for iframe or HTML content invoking custom URI schemes (e.g., 'origin://') with argument injection patterns, particularly when opened in Internet Explorer or legacy browsers that do not encode special characters.
  • ·The .URL file attack vector bypasses modern browser protections (including Edge smart-scan) and works on fully updated Windows 10, making it a higher-risk delivery mechanism requiring social engineering.
  • ·The attacker-controlled Windows share hosting the malicious DLL must contain a subdirectory matching a valid Qt plugin directory name (e.g., 'imageformats') for the DLL to be loaded by the Qt application.

CVSS provenance

nvdv3.07.8HIGHCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.09.3CRITICALAV:N/AC:M/Au:N/C:C/I:C/A:C
vendor_cisco7.8HIGH
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