Microsoft Exchange Server '/Autodiscover' Server Side Request Forgery Security Bypass Vulnerability

2019-12-27T00:00:00
ID SMNTC-111358
Type symantec
Reporter Symantec Security Response
Modified 2019-12-27T00:00:00

Description

Description

Microsoft Exchange Server is prone to a security-bypass vulnerability. Attackers can exploit this issue to bypass certain security restrictions to perform unauthorized actions. This may aid in further attacks. Microsoft Exchange Server 2013 Cumulative Update 22 and prior versions are vulnerable.

Technologies Affected

  • Microsoft Exchange Server 2013 Cumulative Update 1
  • Microsoft Exchange Server 2013 Cumulative Update 10
  • Microsoft Exchange Server 2013 Cumulative Update 11
  • Microsoft Exchange Server 2013 Cumulative Update 12
  • Microsoft Exchange Server 2013 Cumulative Update 13
  • Microsoft Exchange Server 2013 Cumulative Update 14
  • Microsoft Exchange Server 2013 Cumulative Update 16
  • Microsoft Exchange Server 2013 Cumulative Update 17
  • Microsoft Exchange Server 2013 Cumulative Update 18
  • Microsoft Exchange Server 2013 Cumulative Update 19
  • Microsoft Exchange Server 2013 Cumulative Update 2
  • Microsoft Exchange Server 2013 Cumulative Update 20
  • Microsoft Exchange Server 2013 Cumulative Update 21
  • Microsoft Exchange Server 2013 Cumulative Update 22
  • Microsoft Exchange Server 2013 Cumulative Update 3
  • Microsoft Exchange Server 2013 Cumulative Update 6
  • Microsoft Exchange Server 2013 Cumulative Update 7
  • Microsoft Exchange Server 2013 Cumulative Update 8
  • Microsoft Exchange Server 2013 Cumulative Update 9

Recommendations

Block external access at the network boundary, unless external parties require service.
Filter access to the affected computer at the network boundary if global access isn't needed. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.

Run all software as a nonprivileged user with minimal access rights.
When possible, run all software as a user with minimal privileges and limited access to system resources. Use additional precautions such as restrictive environments to insulate software that may potentially handle malicious content.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review its logs regularly.

Currently, we are not aware of any vendor-supplied patches. If you feel we are in error or if you are aware of more recent information, please mail us at: vuldb@securityfocus.com.