Summary

• A vulnerability in the loading mechanism of specific dynamic link libraries in Cisco Jabber for Windows could allow an authenticated, local attacker to perform a DLL preloading attack. To exploit this vulnerability, the attacker would need to have valid credentials on the Windows system.

  The vulnerability is due to insufficient validation of the resources loaded by the application at run time. An attacker could exploit this vulnerability by crafting a malicious DLL file and placing it in a specific location on the targeted system. The malicious DLL file would execute when the Jabber application launches. A successful exploit could allow the attacker to execute arbitrary code on the target machine with the privileges of another user's account.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-jabber-dll

Affected Products

• Vulnerable Products

  This vulnerability affects all Cisco Jabber for Windows software releases earlier than the following releases:

  • 12.7.4
  • 12.8.5
  • 12.9.5
  • 14.0

  Products Confirmed Not Vulnerable

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.

  Cisco has confirmed that this vulnerability does not affect the following Cisco products:

  • Jabber for Android
  • Jabber for iPhone and iPad
  • Jabber for Mac

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:
  https://www.cisco.com/c/en/us/products/end-user-license-agreement.html

  Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.

  When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Customers Without Service Contracts

  Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC:
  https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html

  Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.

  Fixed Releases

  Cisco fixed this vulnerability in the following Cisco Jabber for Windows software releases:

  • 12.7.4
  • 12.8.5
  • 12.9.5
  • 14.0

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

• Cisco would like to thank security researcher "wjcsharp" for reporting this vulnerability.

  Cisco would like to thank Hou JingYi of Qihoo 360 CERT for also reporting this vulnerability.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-jabber-dll

Revision History

• Version	Description	Section	Status	Date
  1.2	Added information about additional software fixes because of a regression that reintroduced this vulnerability in subsequent software versions.	Vulnerable Products and Fixed Software	Final	2021-APR-01
  1.1	Updated fixed release to 12.6(2).	Vulnerable Products and Fixed Releases	Final	2019-JUL-03
  1.0	Initial public release.	-	Final	2019-JUL-03

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